Complex Aldol Reactions for the Construction of Dense Polyol Stereoarrays: Synthesis of the C33−C36 Region of Aflastatin A
摘要:
Facial selectivity in the addition of boron enolates of alpha-oxygenated ketones to anti-disposed alpha,beta-bisalkoxy aldehydes is controlled by the aldehyde vicinal diol protecting group. Protection of the diol as an acetonide results in the exclusive formation of the anti-syn-anti stereoarray found in the C-33-C-36 region of aflastatin A.