(a) The transformation shown in Fig. P28.50, which involves a sequence of two pericyclic reactions, was used as a key step in a synthesis of the sex hormone estrone. Identify the unstable intermediate A, and give the mechanism for both its formation and its subsequent reaction.

(b) Show how the product of part (a) can be converted into estrone.

Transcribed Image Text:

HO H H Me 0 H estrone