(–)-Quinic acid in organic synthesis. Part 4. Syntheses of cyclophellitol and its (1R, 6S)-, (2S)-, (1R, 2S, 6S)-diastereoisomers
Abstract
Cyclophellitol 1 and its (1R, 6S)-, (2S)-, (1R, 2S, 6S)-diastereoisomers 2, 3 and 4 are constructed from quinic acid involving the following key steps: regioselective cyclic sulfate ring opening, regiospecific oxidative elimination and an epoxidation. Diastereoisomers 1, 2, 3 and 4 are characterized as their corresponding tetraacetates 5, 6, 7 and 8.