Synthetic Studies of the HIV-1 Protease Inhibitive Didemnaketals: Stereocontrolled Synthetic Approach to the Key Mother Spiroketals

摘要

The stereocontrolled synthesis of (2S,4R,6R,8S,10S,1'R,1"R)-2(acethlhydroxymethyl)-4,10-dimethyl-(isopropenylhydroxymethyl)-1,7-dioxaspiro[5,5]-undecane (4a) and its C1"-epimer (4b), the key mother spiroketals of the HIV-1 protease inhibitive didemnaketals from the ascidian Didemum sp., has been carried out through multisteps from the natural (R)-(+)-pulegone,which involved the diastereoselective construction of four chiral carbon centers (C-2,C-6,C-8,and C-1') by intramolecular chiral induce.