Q.30-7 - Organic Chemistry (Mcmurry)

Question

Classify the following sigmatropic reaction by order [x,y], and tell whether itwill proceed with suprafacial or antarafacial stereochemistry:

Step-by-Step Solution

Answer

This can be classified as [1,7] – Antarafacial reaction. There are 3 double bonds contributing 6 electrons and a single bond contributing 2 electrons. Therefore there are total of 8 electrons. Which would be antiaromatic. So, the reaction is achieved by Antarafacial reaction

The classification of reaction.

This can be classified as [1,7] – Antarafacial reaction. There are 3 double bonds contributing 6 electrons and a single bond contributing 2 electrons. Therefore there are total of 8 electrons. Which would be antiaromatic. So, the reaction is achieved by Antarafacial reaction

Steps involve during conversion.

By numbering molecule in reactant side, one can observe that it is a [1,7] – Antarafacial reaction which involve breaking of bond which is attached to Hydrogen atom shown in figure at carbon number 1. The reaction is shown below in figure: