Robinson Annulation $-$ Practice

Compound $1$ is a key intermediate in the synthesis of female hormone estrone. Draw

the starting materials A and $B$ needed to synthesize it by a Robinson annulation:

Identify the double bond formed at the final step of the annulation.

Identify the position of the carbonyl group which underwent nucleophilic addition

with enolate.

Identify the structure of the second enolate formed during the annulation.

Identify the site of initial Michael addition.

Draw the structures of A and $B$