Question

Using only \(\mathrm{C}, \mathrm{H}\), and \(\mathrm{O}\), write structural formulas for the lowest-molecular-weight chiral. (a) Alkane (b) Alcohol (c) Aldehyde (d) Ketone (e) Carboxylic acid (f) Carboxylic ester

Short answer

Answer: The structural formulas for the lowest molecular weight chiral compounds are as follows: a) Alkane: H | C(CH3)-C-CH2-CH3 | H (3-methylhexane) b) Alcohol: H-C-CH3 | OH-C-CH3 (2-butanol) c) Aldehyde: H | H-C-CHO | CH3-CH (2-methylpropanal) d) Ketone: CH3-CH | C=O | CH3-CH (3-methyl-2-butanone) e) Carboxylic acid: H | H-C-COOH | CH3-CH (2-methylpropanoic acid) f) Carboxylic ester: H | H-C-COOCH3 | CH3-CH (methyl 2-methylpropanoate)

Step-by-step solution

a) Alkane

Alkanes are hydrocarbons with only single bonds. The simplest chiral alkane contains four unique groups bonded to a central carbon atom. The lowest-molecular-weight chiral alkane would be 3-methylhexane. Its structural formula: H | C(CH3)-C-CH2-CH3 | H

b) Alcohol

Alcohols contain an -OH group. The simplest chiral alcohol contains a carbon bonded to three unique groups and an OH group. The lowest-molecular-weight chiral alcohol would be 2-butanol. Its structural formula: H-C-CH3 | OH-C-CH3

c) Aldehyde

Aldehydes contain a carbonyl group (C=O) bonded to a hydrogen atom. The smallest chiral aldehyde would be 2-methylpropanal. Its structural formula: H | H-C-CHO | CH3-CH

d) Ketone

Ketones contain a carbonyl group (C=O) within the carbon chain. The smallest chiral ketone would be 3-methyl-2-butanone. Its structural formula: CH3-CH | C=O | CH3-CH

e) Carboxylic acid

Carboxylic acids contain a carbonyl group (C=O) bonded to an OH group. The smallest chiral carboxylic acid would be 2-methylpropanoic acid. Its structural formula: H | H-C-COOH | CH3-CH

f) Carboxylic ester

Carboxylic esters contain a carbonyl group (C=O) bonded to an OR group (where R is an alkyl group). The smallest chiral carboxylic ester would be methyl 2-methylpropanoate. Its structural formula: H | H-C-COOCH3 | CH3-CH