Synthetic studies of the HIV-inhibitive marine natural products: Synthesis of the C1 ∼ C7 fragment of didemnaketal A

The stereoselective synthesis of the C1 ∼ C7 fragment (3R,4S,6R) -3, 4-di [ (tert-butyl dimethylsilyl)-oxy]-7-hydroxy-6-methylheptan-2-one, which is the crucial intermediate for synthesis of the HIV-1 protease inhibitive didemnaketals, was achieved from the natural ( + )-pulegone via a series of the intramolecular chiral induction.