Enantiospecific total synthesis of (-)-megaphone by a highly controlled consecutive 1,4- and 1,3-asymmetric induction

Enantiospecific total synthesis of (-)-megaphone (1) is reported. The key synthetic tactic is the use of (4$\text{S}$)-2$\text{Z}$-ethylidene-4-trityloxymethyl-butan-4-olide (6) to both establish the relative and absolute stereochemistry of the contiguous tertiary and quaternary carbon centers by a highly controlled 1,4- and 1,3-asymmetric induction and construct the 4-methoxy-6,6-dialkyl-cyclohexenone portion of 1.