A somewhat unusual synthesis of cortisone-related steroids includes the following two reactions. CH3 OC(CH;); (CH.),CO K', benzene

A somewhat unusual synthesis of cortisone-related steroids includes the following two reactions. 

(a) Propose mechanisms for these two transformations. Be careful in choosing the initial site of deprotonation in the starting enone. The alkenyl hydrogen, in particular, is not acidic enough to be the one initially removed by base in this reaction. 

(b) Propose a sequence of reactions that will connect the carbons marked by arrows in the third structure shown to form another six-membered ring.

Transcribed Image Text:

CH3 OC(CH;); (CH.),CO K', benzene OC(CH,); + CH,CHCH,CH,Br CH3 OCCCH;)3 CH.I, (CH).CO K", benzene OC(CH3)3 CH3 H;C OC(CH;)3 (CH3);CO