摘要:
The streamlined assembly of the ansamacrolide framework of the kedarcidin chromophore via an efficient atropselective Sonogashira coupling step is described. To this end, two newly improved practical syntheses of the cyclopentene and diyne fragments have been developed, which feature 0.2 mol % catalytic loadings for an RCM step and 1-PrMgCl/CH(2)l(2) as a new entry to gem-disubstituted epoxides from ketones. both being applicable to 49-g scales.