Provide the needed starting material, reagents, or products for each step of the overall synthesis problems below.
Expert Answer
1. Please check the attached figure. Initially, acetylene upon treatment with n-BuLi and decyl bromide gives compound A. Compound A upon treatment with n-BuLi and alkyl bromide gives compound B. Now alkyne group in compound B can be reduced to alkene using Lindler catalyst (Pd partially poisoned with quinoline) to give Cis-alkene C which further oxidation with mCPBA gives epoxide D.
On the other hand, aldehyde upon treatment with methyl Grignard gives alcohol E which upon oxidation gives ketone F. The 1-carbon Wittig olefination gives alkene G. Now compound G, upon treatment with borane.THF followed by H2O2/NaOH gives primary alcohol H which upon reaction with TsCl and base gives corresponding tosylate (K) The tosylate can be displaced with enolate ion gives ketone I which on acidic hydrolysis deprotects acetal and gives diol J. Under the similar condition, compound J will be cyclized again to give our final compound.