Alcohol, Phenol and Ether - Classification, Preparation with FAQs

Alcohol Phenol and Ether - Classification, Preparation with FAQs

Edited By Team Careers360 | Updated on Jul 02, 2025 04:53 PM IST

Alcohol Phenol Ether

The alcohol, phenol and ether are classes of compounds containing a single carbon-oxygen bond that have the following general structures.

Alcohol R-O-H

Phenol carbon-oxygen bond

Ether R-O-R’ (R/R’ may be aromatic)

Ether, alcohol, and phenol are chemical molecules that are widely used in a variety of industries as well as in everyday life.

When a saturated carbon atom is linked to a hydroxyl (-OH) group, alcohol is produced. When a hydrogen atom in a benzene molecule is replaced by the -OH group, phenol is produced. It means a phenol contains a hydroxyl group (-OH) directly attached to carbon atom present in an aromatic compound. In alcohol one or more hydroxyl group is directly attached to carbon atom present in an aliphatic compound.

When an oxygen atom is joined to two alkyl or aryl groups, ether is produced. It means substitution of an alkoxy or aryloxy group (R–O/Ar–O) for a hydrogen atom in a hydrocarbon such as CH₃OCH₃ (dimethyl ether).

Also read -

This Story also Contains

Alcohol Phenol Ether
Alcohols
Phenols
Ethers

Alcohols

Nomenclature of Alcohol

The word "alcohol" is added to the name of the alkyl group, for example, methyl alcohol, ethyl alcohol, and so on.

IUPAC - The suffix ‘ol' added to the name of an alkane, for example, methanol (CH₃OH), ethanol (C₂H₅OH), and so on.

Classification of Alcohols or types of alcohols

Alcohols are classified into mono-, di-, tri- or polyhydric compound. This classification is done depending on the hydroxyl groups attached to the compound. Monohydric alcohols are those that have only one -OH group. For instance, CH₃CH₂-OH.Two -OH groups are found in dihydric alcohols, example is 1,2-Ethandiol.. There are three -OH groups in trihydric alcohols, example is 1,2,3-Propantriol.

Monohydric CH₃-CH₂-OH

Dihydric

Trihydric

Monohydric alcohols are further classified depending on the hybridization of carbon atom to which hydroxyl group is attached.

The carbon containing sp³hybridisation- In this hydroxyl group is attached to the carbon atom having sp³ hybridisation. They are further divided into the following categories: primary, secondary, and tertiary alcohols: The –OH group is connected to the primary, secondary, and tertiary carbon atoms in these three forms of alcohols, as shown below:

R-CH₂ –OH R₂-CH-OH R₃-C-OH

(Primary) (Secondary) (Tertiary)

Allylic alcohols: In these type alcohols, the —OH group is connected to a sp³ hybridised carbon adjacent to the carbon-carbon double bond that is to an allylic carbon.

Benzylic alcohols: In these types of alcohols, the —OH group is connected to a sp³—hybridised carbon atom next to an aromatic ring. e.g. CH₂=CH-CH-OH

Vinylic alcohol: In these type alcohols, the – OH group connected to C (sp2) with C=C, e.g. CH₂=CH-OH

Compounds containing C_sp²-OH bond: The —OH group is attached to a carbon-carbon double bond, such as a vinylic carbon or an aryl carbon, in these alcohols. Vinylic alcohols are another name for these alcohols.

Vinylic alcohol: CH₂= CH – OH

Also read :

Preparation of Alcohol

From Alkenes:

NEET Highest Scoring Chapters & Topics

This ebook serves as a valuable study guide for NEET exams, specifically designed to assist students in light of recent changes and the removal of certain topics from the NEET exam.

Download EBook

a. Acid-catalyzed hydration- Markonikov's rule-based H₂O addition.

b. Hydroboration-oxidation- Reaction with diborane to produce trialkyl boranes, which are then oxidised with H₂O₂ and NaOH (aq).

The end result is the total opposite of Markonikov's rule.

From Grignard Reagents:

Grignard reagent(R-Mg-X) is used to react with aldehydes and ketones. The Grignard reagent is added nucleophilically and then hydrolysed.

HCHO + RMgX → RCH₂OMgX + H₂O → RCH₂OH + Mg(OH)X

Chemical Reactions of Alcohol

Alcohol reacts as a nucleophile in the following reactions (O-H bond cleavage):

a. Metals react with alkoxides and H₂ to create the corresponding alkoxides and H₂.

2R-O-H + 2Na → 2R-O-Na + H₂

b. Esterification: Alcohols form esters when they react with carboxylic acids, acid anhydrides, and acid chlorides.

Alcohol interacts as an electrophile (C-O bond cleavage) in the following reactions:

a. Alkyl halides are formed by reacting with HX. The Lucas test, which distinguishes between 1°, 2°, and 3° alcohols, is based on this.

As 3° alcohols easily form halides, turbidity is formed almost immediately.

b. Alkyl halides are formed by reacting with PX₃.

c. Dehydrate to create alkene in the presence of protic acid, e.g., Ethanol reacts with H₂SO₄ at 443 K to form ethylene.

Dehydration of 2° and 3° alcohols occurs under more mild conditions. The order of dehydration is:

3° > 2° > 1°

d. Aldehyde and ketone formation via oxidation or dehydrogenation

Aldehydes are formed from primary alcohols.

Carboxylic acid is formed directly by strong oxidising agents (KMnO₄).

Aldehydes are made with CrO₃ and PCC (pyrimidine chlorochromate).

When secondary alcohols are oxidised by CrO₃, they produce ketones. Tertiary alcohols are unaffected by oxidation. Dissociation of the C-C bond occurs when KMnO₄ is applied at a higher temperature, resulting in a variety of carboxylic acids with fewer carbon atoms.

e. When alcohols are heated with Cu at 573 K, they dehydrate.

1° alcohol → Aldehyde

2° alcohol → Ketone

3° alcohol → Alkene (Dehydration)

Phenols

Nomenclature of Phenols

Phenol (C₆H₅OH) is the most basic. It is the common name, and it is also accepted by the International Union of Scientific Organizations (IUPAC).The OH group's position is indicated by the letters o (ortho), m (meta), p (para), or by numbering the cyclic carbons.

For example, 2-Methylphenol is o-Cresol, while Benzene-1,2-diol is Catechol.

Classification of Phenols or types of phenol

Monohydric : Monohydric phenols are phenols with only one -OH group.

Dihydric : Two -OH groups are found in dihydric phenols. They can be ortho, meta or para derivatives.

Trihydric : Three -OH groups are found in trihydric phenols.

Preparation of Phenols

From Haloarenes:

Chlorobenzene is converted to sodium phenoxide by reacting with NaOH, which is subsequently converted to phenol by reacting with acid.

C₆H₅Cl + NaOH → C₆H₅ONa + HCl → C₆H₅OH

From Benzene sulphonic Acid:

Sulphonation of benzene with oleum is the initial stage. The resulting benzene sulphonic acid is heated with molten NaOH to generate sodium phenoxide, which is subsequently acidified to get phenol.

From Cumene:

Cumene (isopropylbenzene) is oxidised to cumene hydroperoxide, which is then treated with dilute acid to produce phenol. The reaction produces acetone as a by-product.

Chemical Reaction of Phenols

Nucleophilic reactions using phenol (O-H bond cleavage):

a. Phenol becomes sodium phenoxide when it interacts with metal or aqueous NaOH.

b. Esterification: Phenols create esters when they react with carboxylic acids, acid anhydrides, and acid chlorides.

Salicylic acid + Acetic anhydride → Aspirin (Acetylsalicylic acid)

C-O bond cleavage reactions:

Benzene is formed when phenol interacts with zinc dust.

C₆H₅OH + Zn → C₆H₆ + ZnO

Phenols are categorised into three categories based on the amount of hydroxyl groups attached.

Related Topics Link,

Ethers

Nomenclature of Ethers

Common Name – Ethyl methyl ether, Diethyl ether, and so on are examples of the word ‘ether’ following the names of the alkyl groups in alphabetical sequence.

IUPAC Name – A hydrocarbon derivative known as an alkoxy or aryloxy derivative. The parent hydrocarbon is the bulkier group, such as methoxymethane, methoxybenzene, and so on.

Classification of Ethers or types of ethers

Ether can be categorised into two categories based on the type of alkyl or aryl groups connected to the oxygen atom.

Symmetrical ether: The alkyl or aryl group linked to each side of the oxygen atoms is the same in symmetrical ether, also known as the simple ether. CH₃OCH₃, C₂H₅OC₂H₅, and so on are examples.

Unsymmetrical ether: The alkyl or aryl groups linked to either side of the oxygen atoms are not the same in unsymmetrical ether, often known as the mixed either. CH₃OC₂H₅, C₂H₅OC₆H₅, and so on are examples.

Preparation of Ethers

Alcohols are dehydrated in the following ways:

The nucleophilic bimolecular reaction forms ether when primary alcohols are treated with protic acids (H₂SO₄, H₃PO₄). This reaction is temperature dependent; alkene is a main product at 443 K, but ether is obtained as a main product at 413 K.

In elimination reaction of secondary or tertiary alcohol, alkene is formed as a main product.

Synthesis by Williamson:

When sodium alkoxide reacts with an alkyl halide, ether is produced.

When using a 1° alkyl halide, S_N² is preferred and ether is formed as a major product; however, when using a 2° or 3° alkyl halide, elimination proceeds and alkene is formed as the major product.

This process can also be used to convert phenol to ether.

Also read -

Chemical Reactions of Ethers

Cleavage of the C-O bond in reactions:

Ethers, on the other hand, are less reactive. Cleavage of the C-O bond happens at extreme circumstances.

When dialkyl ethers react with HX, they produce two alkyl halides.

Because the aryl-oxygen bond is more stable, alkyl aryl ethers react with HX to generate phenol and alkyl halide.

The reactivity order of HX is

HI > HBr > HCl

Substitution of Electrophilic Compounds:

Electrophilic aromatic substitution occurs at the ortho (o) and para (p) positions in aryl ethers.

Friedel's reaction is as follows:

At the o and p positions, halogenation and nitration occur.

In the presence of AlCl₃ (anhydrous), anisole combines with alkyl or acyl halides to produce o and p substituted products.

Also check-

Frequently Asked Questions (FAQs)

1. Write about classification of phenols?

Phenols are classified into monohydric, dihydric and trihydric. Monohydric phenols are phenols with only one -OH group. In Dihydric two -OH groups are found in dihydric phenols. They can be ortho, meta or para derivatives. Three -OH groups are found in trihydric phenols.

2. Write one preparation method of ether?

Synthesis by Williamson: When sodium alkoxide reacts with an alkyl halide, ether is produced.

3. What are 3 classes of alcohol?

Primary alcohol, secondary alcohol and tertiary alcohol are 3 types of alcohol.

4. Write about Nomenclature of ether?

Common Name – Ethyl methyl ether, Diethyl ether, and so on are examples of the word ‘ether’ following the names of the alkyl groups in alphabetical sequence. IUPAC Name – A hydrocarbon derivative known as an alkoxy or aryloxy derivative. The parent hydrocarbon is the bulkier group, such as methoxymethane, methoxybenzene, and so on.

5. Write any one chemical reaction of phenol?

Esterification: Phenols create esters when they react with carboxylic acids, acid anhydrides, and acid chlorides.

Salicylic acid + Acetic anhydride → Aspirin (Acetylsalicylic acid)

6. What are the uses of alcohol, phenol and ether?

Antiseptics, detergents are mainly prepared using alcohol phenol ether.

7. Is ether and alcohol the same?

Ether and alcohol are different but ether has a similar structure as alcohol.

8. What are the main classes of alcohols, and how are they distinguished?

Alcohols are classified into three main types: primary, secondary, and tertiary. They are distinguished by the number of carbon atoms directly bonded to the carbon bearing the hydroxyl (-OH) group. Primary alcohols have one carbon attached, secondary have two, and tertiary have three.

9. Why are alcohols more soluble in water compared to alkanes of similar molecular weight?

Alcohols are more soluble in water due to their ability to form hydrogen bonds with water molecules through their -OH group. Alkanes lack this polar group and cannot form hydrogen bonds, making them less soluble in water.

10. How does the boiling point of alcohols change as the carbon chain length increases?

As the carbon chain length of alcohols increases, the boiling point generally increases. This is due to stronger van der Waals forces between longer molecules, which require more energy to overcome during boiling.

11. What is the difference between hydration and hydrolysis in alcohol preparation?

Hydration involves the addition of water to an alkene to form an alcohol, while hydrolysis involves the breakdown of a compound by reaction with water. In alcohol preparation, hydration of alkenes produces alcohols, while hydrolysis of alkyl halides can also yield alcohols.

12. How does the reactivity of primary, secondary, and tertiary alcohols differ in elimination reactions?

The reactivity order for elimination reactions is tertiary > secondary > primary. This is because more substituted alcohols form more stable carbocations as intermediates, making the elimination reaction more favorable.

13. What is the general structure of ethers, and how does it relate to alcohols?

Ethers have the general structure R-O-R', where R and R' are alkyl or aryl groups. They can be thought of as two alkyl groups connected by an oxygen atom, similar to an alcohol where one hydrogen of the -OH group is replaced by another alkyl group.

14. What is the Williamson ether synthesis, and why is it important?

The Williamson ether synthesis is a method for preparing ethers by reacting an alkoxide ion with an alkyl halide. It's important because it allows for the controlled synthesis of both symmetrical and unsymmetrical ethers, which are useful in various applications.

15. How does the structure of ethers contribute to their relatively low boiling points compared to alcohols?

Ethers have lower boiling points than alcohols of similar molecular weight because they cannot form hydrogen bonds with each other. The oxygen in ethers can only participate in weaker dipole-dipole interactions, resulting in less energy required to overcome intermolecular forces during boiling.

16. What is the difference between anhydrous and aqueous ethers, and why is this distinction important?

Anhydrous ethers are free from water, while aqueous ethers contain water. This distinction is crucial because anhydrous ethers are often used as solvents in reactions that are sensitive to water, such as organometallic reactions. The presence of water can lead to unwanted side reactions or decomposition of reagents.

17. What is the importance of protecting groups in alcohol chemistry, and can you give an example?

Protecting groups are used to temporarily mask the reactivity of the -OH group in alcohols during multi-step syntheses. This allows for selective reactions at other parts of the molecule. An example is the use of silyl ethers (e.g., TBS ethers) to protect alcohols during reactions that might otherwise affect the -OH group.

18. How does the structure of phenols differ from alcohols?

Phenols have a hydroxyl (-OH) group directly attached to an aromatic ring, while alcohols have the -OH group attached to an alkyl group. This structural difference leads to significant variations in their properties and reactivity.

19. How does the acidity of phenols compare to that of alcohols?

Phenols are generally more acidic than alcohols. This is because the aromatic ring in phenols can stabilize the resulting phenoxide ion through resonance, making it easier for phenols to lose a proton compared to alcohols.

20. How does the presence of an -OH group affect the reactivity of the benzene ring in phenols?

The -OH group in phenols activates the benzene ring towards electrophilic aromatic substitution reactions. It directs incoming electrophiles to the ortho and para positions due to resonance effects, making phenols more reactive than benzene in these types of reactions.

21. How does the presence of electron-withdrawing or electron-donating groups affect the acidity of phenols?

Electron-withdrawing groups (e.g., -NO2, -CN) increase the acidity of phenols by stabilizing the phenoxide ion through resonance and inductive effects. Electron-donating groups (e.g., -CH3, -OCH3) decrease acidity by destabilizing the phenoxide ion.

22. How does hydrogen bonding affect the physical properties of alcohols?

Hydrogen bonding between alcohol molecules leads to higher boiling points, increased viscosity, and greater solubility in water compared to hydrocarbons of similar molecular weight. This is because hydrogen bonds are stronger than typical intermolecular forces.

23. What is the mechanism of alcohol dehydration, and what factors affect the products formed?

Alcohol dehydration involves the loss of water to form an alkene. The mechanism typically involves protonation of the -OH group, followed by loss of water to form a carbocation, and then loss of a proton to form the alkene. The major product depends on Zaitsev's rule, which states that the more substituted alkene is usually the major product.

24. What is the difference between SN1 and SN2 reactions in alcohol substitution?

SN1 (unimolecular nucleophilic substitution) involves a carbocation intermediate and is favored by tertiary alcohols. SN2 (bimolecular nucleophilic substitution) involves a concerted mechanism and is favored by primary alcohols. Secondary alcohols can undergo either mechanism depending on conditions.

25. What is the Lucas test, and how is it used to distinguish between different types of alcohols?

The Lucas test uses a mixture of zinc chloride and concentrated hydrochloric acid to distinguish between primary, secondary, and tertiary alcohols. Tertiary alcohols react immediately, forming an insoluble alkyl chloride layer. Secondary alcohols react within 5 minutes, while primary alcohols react slowly or not at all at room temperature.

26. How does the oxidation of primary, secondary, and tertiary alcohols differ?

Primary alcohols can be oxidized to aldehydes and then to carboxylic acids. Secondary alcohols are oxidized to ketones. Tertiary alcohols do not undergo simple oxidation reactions under normal conditions due to the lack of a hydrogen atom on the carbon bearing the -OH group.

27. What is the Grignard reaction, and how is it used in alcohol synthesis?

The Grignard reaction involves the addition of a Grignard reagent (RMgX) to a carbonyl compound. When added to aldehydes or ketones, it produces alcohols upon workup. This reaction is valuable for forming new carbon-carbon bonds and synthesizing alcohols with specific structures.

28. How does the crown ether structure contribute to its unique properties and applications?

Crown ethers have a cyclic structure with multiple ether oxygen atoms arranged in a ring. This structure allows them to complex with metal cations, making them useful in phase-transfer catalysis, ion transport, and selective metal extraction. The size of the ring determines which cations can be complexed most effectively.

29. What is the pinacol rearrangement, and how does it relate to alcohol chemistry?

The pinacol rearrangement is an acid-catalyzed rearrangement of 1,2-diols (vicinal diols) to form carbonyl compounds. It involves the migration of an alkyl group and the loss of water. This reaction is important in understanding the behavior of diols and the formation of carbonyl compounds from alcohols under acidic conditions.

30. How does the structure of phenol contribute to its ability to act as an antioxidant?

The phenolic -OH group can donate a hydrogen atom to free radicals, neutralizing them and forming a relatively stable phenoxy radical. This radical is stabilized by resonance with the aromatic ring, making phenols effective antioxidants in various applications, including food preservation and polymer stabilization.

31. What is the difference between a hemiacetal and an acetal, and how are they formed from alcohols?

A hemiacetal has one alkoxy group (-OR) and one -OH group on the same carbon, while an acetal has two alkoxy groups. Hemiacetals form when an alcohol adds to an aldehyde or ketone. Acetals form when a hemiacetal reacts with another alcohol molecule, usually under acidic conditions. Both are important in carbohydrate chemistry and protecting group strategies.

32. How does the presence of an alpha-hydrogen affect the reactivity of ethers?

Ethers with an alpha-hydrogen (a hydrogen on the carbon adjacent to the oxygen) can undergo cleavage reactions, especially under acidic conditions or when exposed to strong bases at high temperatures. This reactivity is important in ether synthesis planning and in understanding ether stability.

33. What is the Kolbe-Schmitt reaction, and how is it related to phenol chemistry?

The Kolbe-Schmitt reaction is the carboxylation of sodium phenoxide with carbon dioxide under pressure, followed by acidification, to produce salicylic acid. This reaction demonstrates the nucleophilicity of the phenoxide ion and is industrially important for the production of aspirin precursors.

34. How does the presence of intramolecular hydrogen bonding affect the boiling points of certain alcohols?

Intramolecular hydrogen bonding, which can occur in molecules like ethylene glycol, reduces the extent of intermolecular hydrogen bonding. This can lead to lower boiling points than expected based solely on molecular weight. However, the overall effect on boiling point depends on the balance between intra- and intermolecular hydrogen bonding.

35. What is the difference between a phenol and an enol, and how does this affect their reactivity?

A phenol has an -OH group directly attached to an aromatic ring, while an enol has an -OH group attached to a carbon involved in a carbon-carbon double bond. Phenols are generally more stable and less reactive than enols due to the aromatic stabilization. Enols often tautomerize to their keto form, while phenols do not undergo this type of tautomerization.

36. How does the Williamson ether synthesis differ from the etherification of alcohols using acid catalysts?

The Williamson ether synthesis uses an alkoxide ion and an alkyl halide to form ethers under basic conditions, allowing for the synthesis of both symmetrical and unsymmetrical ethers. Acid-catalyzed etherification of alcohols typically leads to symmetrical ethers and can suffer from side reactions like elimination. The Williamson synthesis offers more control over the products formed.

37. What is the mechanism of the Fries rearrangement, and how does it relate to phenol chemistry?

The Fries rearrangement involves the conversion of phenyl esters to hydroxyaryl ketones. It's typically catalyzed by Lewis acids like AlCl3. The mechanism involves the formation of an acylium ion, which then attacks the aromatic ring. This reaction demonstrates the electrophilic aromatic substitution reactivity of phenol derivatives and is useful in synthesizing hydroxyarylketones.

38. How does the presence of fluorine substituents affect the acidity of alcohols and phenols?

Fluorine substituents increase the acidity of alcohols and phenols through inductive effects. The highly electronegative fluorine atoms withdraw electron density from the O-H bond, making it easier to lose a proton. This effect is more pronounced in phenols due to the direct conjugation with the aromatic ring.

39. What is the difference between a glycol and a diol, and how does this affect their reactivity?

While both glycols and diols are compounds with two hydroxyl groups, the term "glycol" typically refers to vicinal diols (with -OH groups on adjacent carbons), like ethylene glycol. Diols can have -OH groups in any position. Vicinal diols can undergo specific reactions like periodate cleavage and pinacol rearrangement, which are not possible for diols with more separated -OH groups.

40. How does the presence of an ether linkage affect the boiling point of a compound compared to its alcohol analog?

Ethers generally have lower boiling points than their alcohol analogs of similar molecular weight. This is because ethers cannot form hydrogen bonds with each other, while alcohols can. The oxygen in ethers can only participate in weaker dipole-dipole interactions, resulting in less energy required to overcome intermolecular forces during boiling.

41. What is the Prilezhaev reaction, and how is it used in alcohol synthesis?

The Prilezhaev reaction is the epoxidation of alkenes using peroxyacids, such as m-chloroperoxybenzoic acid (mCPBA). The resulting epoxide can be opened with water or other nucleophiles to form alcohols. This reaction is valuable for introducing hydroxyl groups in a stereospecific manner, particularly in complex molecule synthesis.

42. How does the presence of an alpha-carbonyl group affect the acidity of alcohols?

An alpha-carbonyl group significantly increases the acidity of an alcohol. This is due to the stabilization of the resulting alkoxide ion through resonance with the carbonyl group. This effect is important in many biochemical processes, such as the aldol condensation, and in the reactivity of compounds like beta-keto alcohols.

43. What is the difference between a phenol and a phenoxide ion in terms of aromaticity?

Both phenol and the phenoxide ion are aromatic, but the phenoxide ion has enhanced aromaticity. The negative charge on the oxygen in the phenoxide ion is delocalized into the ring, contributing an additional resonance structure. This increased delocalization makes the phenoxide ion more stable and more aromatic than the neutral phenol.

44. How does the presence of intramolecular hydrogen bonding affect the solubility of certain alcohols in non-polar solvents?

Intramolecular hydrogen bonding can increase the solubility of certain alcohols in non-polar solvents. By satisfying their hydrogen bonding capacity internally, these molecules become less polar overall, making them more soluble in non-polar solvents. This effect is seen in compounds like salicylic acid, where the -OH group can hydrogen bond with the adjacent carbonyl group.

45. What is the Ritter reaction, and how is it used in the synthesis of amides from alcohols?

The Ritter reaction is a method for converting tertiary alcohols or alkenes into amides using concentrated sulfuric acid and a nitrile. For alcohols, the mechanism involves the formation of a carbocation, followed by nucleophilic attack by the nitrile and subsequent hydrolysis. This reaction is useful for introducing amide functionalities into molecules, starting from readily available alcohols.

46. How does the presence of an ether linkage affect the reactivity of adjacent carbon-hydrogen bonds?

The ether oxygen can stabilize adjacent carbocations through resonance, making reactions that proceed through carbocation intermediates more favorable at these positions. This is known as the alpha-effect and is important in reactions like the formation of oxonium ions. However, ethers are generally less reactive than alcohols due to the lack of an easily removable proton.

47. What is the Oppenauer oxidation, and how does it compare to other alcohol oxidation methods?

The Oppenauer oxidation is a method for oxidizing secondary alcohols to ketones using aluminum alkoxides and a ketone as the oxidant (often acetone). It's particularly useful for oxidizing sensitive compounds that might not tolerate harsher oxidizing agents. Unlike chromium-based oxidations, it doesn't over-oxidize primary alcohols to carboxylic acids, making it more selective in some cases.

48. How does the presence of multiple hydroxyl groups affect the reactivity of carbohydrates compared to simple alcohols?

Carbohydrates with multiple hydroxyl groups exhibit more complex reactivity than simple alcohols. They can form intramolecular and intermolecular hydrogen bonds, affecting solubility and reactivity. The presence of multiple -OH groups allows for selective protection and derivatization, important in carbohydrate chemistry. Additionally, they can undergo cyclization reactions to form hemiacetals and acetals, a key feature in their structural diversity.

49. What is the difference between a phenol and a thiophenol in terms of acidity and reactivity?

Thiophenols (ArSH) are generally more acidic than phenols (ArOH) due to the larger size and higher polarizability of sulfur compared to oxygen. This makes the S-H bond weaker and easier to break. However, thiophenols are less reactive in electrophilic aromatic substitution