The stereocontrolled synthesis of (2S,4R,6R,8S,10S,1'R,1"R)-2(acetylhydroxy
ane (4a) and its C1"-epimer (4b), the key mother spiroketals of the HIV-1 p
rotease inhibitive didemnaketals from the ascidian Didemnum sp., has been c
arried out through multisteps from the natural (R)-(+)-pulegone, which invo
lved the diastereoselective construction of four chiral carbon centers(C-2,
C-6, C-8, and C-1') by intramolecular chiral induce.