Chapter 13, Problem 13.31P

Interpretation Introduction

(a)

Interpretation:

A synthetic step for the given transformation, including reagents and special reaction conditions in the forward direction, is to be written.

Concept introduction:

Synthesis may be designed by thinking in the reverse direction, from the product to the starting compound, in a method called retrosynthesis. A synthesis is a specific sequence of chemical reactions that converts the starting materials into the desired compound, called the target (or synthetic target). The product given in the retrosynthetic step is the precursor for the synthetic step, followed by an arrow $\text{(}\to \text{)}$ with reaction conditions and the product (precursor in the retrosynthetic step) is the synthetic step.

Alkene to amine is a retrosynthethic approach of Hofmann elimination reaction.

The Hofmann elimination reaction leads to an anti-Zaitsev elimination product or Hofmann product. An amine with a poor leaving group is converted into a tetraalkyl ammonium ion, which has a moderately good leaving group, using excess of an alkyl halide like ${\text{CH}}_{\text{3}}\text{I}$. Subsequent treatment with ${\text{Ag}}_{\text{2}}\text{O}$, followed by heat, induces elimination.

Interpretation Introduction

(b)

Interpretation:

A synthetic step for the given transformation, including reagents and special reaction conditions in the forward direction, is to be written.

Concept introduction:

Synthesis may be designed by thinking in the reverse direction, from the product to the starting compound, in a method called retrosynthesis. A synthesis is a specific sequence of chemical reactions that converts the starting materials into the desired compound, called the target (or synthetic target). The product given in the retrosynthetic step is the precursor for the synthetic step, followed by an arrow $\text{(}\to \text{)}$ with reaction conditions and the product (precursor in the retrosynthetic step) is the synthetic step.

Reaction with LDA leads to alkylation at the less highly alkyl substituted carbon atom.

Interpretation Introduction

(c)

Interpretation:

A synthetic step for the given transformation, including reagents and special reaction conditions in the forward direction, is to be written.

Concept introduction:

Synthesis may be designed by thinking in the reverse direction, from the product to the starting compound, in a method called retrosynthesis. A synthesis is a specific sequence of chemical reactions that converts the starting materials into the desired compound, called the target (or synthetic target). The product given in the retrosynthetic step is the precursor for the synthetic step, followed by an arrow $\text{(}\to \text{)}$ with reaction conditions and the product (precursor in the retrosynthetic step) is the synthetic step.

Esterification is the reaction of acid with diazomethane to form the desired ester as a product.

Interpretation Introduction

(d)

Interpretation:

A synthetic step for the given transformation, including reagents and special reaction conditions in the forward direction, is to be written.

Concept introduction:

Synthesis may be designed by thinking in the reverse direction, from the product to the starting compound, in a method called retrosynthesis. A synthesis is a specific sequence of chemical reactions that converts the starting materials into the desired compound, called the target (or synthetic target). The product given in the retrosynthetic step is the precursor for the synthetic step, followed by an arrow $\text{(}\to \text{)}$ with reaction conditions and the product (precursor in the retrosynthetic step) is the synthetic step.

Most hydrogen halide reactions with alkynes occur in a Markovnikov-manner in which the halide attaches to the most substituted carbon.