Write reagents (a, b, c, d, e) where they have been omitted from the following synthetic sequence. Each letter may correspond to one or more reaction steps. This sequence is the beginning of a synthesis of germanicol, a naturally occurring triterpene. The diol used in the step between (a) and (b) provides selective protection of the more reactive carbonyl group.

See Problem 63 when formulating (b).

Data From Problem 63

(a)

(b)

CH H;C. H;C. H*. HOCH,CH,OH (b) () H3 H;C CH H;C CH 1. Li, liquid NH, 2. () (d) H. H3 H;C CH3