Question

Write structural formulas for these amines. (a) 2-Methyl-1-propanamine (b) Cyclohexanamine (c) \((R)-2\)-Butanamine

Short answer

Question: Draw the structural formulas of the following amines and briefly describe their structures: (a) 2-Methyl-1-propanamine, (b) Cyclohexanamine, (c) (R)-2-Butanamine. Answer: (a) 2-Methyl-1-propanamine has a propane parent chain with an amine functional group on the first carbon and a methyl group on the second carbon. Its structural formula is: H H H | | | H-C-N | | H-C-C-H | | H H (b) Cyclohexanamine has a cyclohexane parent chain with an amine functional group directly connected to the ring. Its structural formula is: H H H H | | | | H H-C-C-C-C-H | | N-H C-C-C-C-H | | | | H H H H (c) (R)-2-Butanamine has a butane parent chain with an amine functional group on the second carbon and the (R)-configuration. Its structural formula is: H H | | (R)-C-C-N | | | H C-C-H | | H H

Step-by-step solution

(a) 2-Methyl-1-propanamine

We begin by identifying the parent chain of the compound. This compound has three carbons; hence, the parent chain is propane. Next, we identify the functional group, which is an amine in this case, and its position on the parent chain (position 1). Lastly, we will identify the position of the methyl group (position 2). Now, we can draw the structural formula: H H H | | | H-C-N | | H-C-C-H | | H H

(b) Cyclohexanamine

In this compound, the parent chain is a cyclohexane, which has six carbons in a ring structure. The amine functional group is directly connected to the ring. Now, we can draw the structural formula: H H H H | | | | H H-C-C-C-C-H | | N-H C-C-C-C-H | | | | H H H H

(c) \((R)-2\)-Butanamine

First, we need to identify the parent chain, which is butane with four carbons. The compound has the amine functional group on the second carbon and the \((R)\)-configuration. We can use the Cahn–Ingold–Prelog priority rules to identify the highest priority groups (1, 2, and 3) and confirm the stereochemistry. Now, we can draw the structural formula: H H | | \((R)\)-C-C-N | | | H C-C-H | | H H