Question

Question:What type of sigmatropic rearrangement is illustrated in each equation?

Short answer

Answer

a. [1,3]-D shift

b. [3,3]-Sigmatropic rearrangement

Step-by-step solution

Sigmatropic rearrangement 

Sigmatropic rearrangement is a type of pericyclic reaction that involves the making and breaking of -bonds in a single system. The -bond rearranges and takes a new position.

An example of 3,3-sigmatropic rearrangement is given below:

Determination of products

a.

In the given reaction, the C-D bond is the sigma bond that breaks, and a new C-D bond forms at the C-3 position.

b.

The given reaction is an example of [3,3]-sigmatropic rearrangement, and the product is given below: