2. Molecular Representations

Which of the following functional groups is present in all amino acids?

Which of the following is a characteristic functional group of alcohols?

How many carbons are in the planar double-bond system in each of the following compounds?

a.

b.

c.

Draw a Lewis structure, and classify each of the following compounds. The possible classifications are as follows:

alcohol

ether

ketone

aldehyde

carboxylic acid

alkene

(h)

(i)

Many naturally occurring compounds contain more than one functional group. Identify the functional groups in the ­following compounds:

a. Penicillin G is a naturally occurring antibiotic.

b. Dopamine is the neurotransmitter that is deficient in Parkinson’s disease.

In 2012, a group led by Professor Masayuki Satake of the University of Tokyo reported the isolation and structure determination of a toxin from a marine algal bloom that decimated the fish population off the New Zealand coast in 1998. Extensive mass spectrometry and NMR experiments ultimately led to the structure shown below, named Brevisulcenal-F. (See Journal of the American Chemical Society, 2012, 134, 4963–4968.) This structure holds the record for the largest number of fused rings, at 17.

(a) How many ether groups are present?

(b) How many alcohol groups are present? Classify the alcohols as 1° or 2° or 3°.

(c) Are there any other oxygen-containing functional groups? Which, if any?

Draw a Lewis structure, and classify each of the following compounds. The possible classifications are as follows:

alcohol

ether

ketone

aldehyde

carboxylic acid

alkene

(a) CH₂CHCHO

(b) CH₃CH₂CH(OH)CH₃

(c) CH₃COCH₂CH₃

Identify the functional groups in each of the following molecules. [The number of functional groups has been given to assist you.]

(a) [Three]

Draw a Lewis structure, and classify each of the following compounds:

(i)

(j)

Circle the functional groups in the following structures. State to which class (or classes) of compounds the structure belongs.

a. CH₂=CHCH₂COOCH₃

b. CH₃OCH₃

c. CH₃CHO

How many hydrogens would you expect a 24-carbon compound from each of the following molecular classes to have?

(b) Alkene

Classify each hydrogen atom in the following compounds as primary (1°), secondary (2°), or tertiary (3°).

c. 2-methylbutane

d. cyclohexane

Identify the functional groups in each of the following molecules. [The number of functional groups has been given to assist you.]

(b) [Two]

Identify the functional groups in each of the following molecules. [The number of functional groups has been given to assist you.]

(c) [Three]