tert-Butanol → tert-butyl (2S,3S,6R,7S,8S)-5-oxo-3-(triethylsilyloxy)-2,4,4,6,8-pentamethyl-7-(2,2,2-trichloroethoxycarbonyloxy)-10-undecenoate

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Reaction Steps

A solution of (2S,3S,6R,7S,8S)-5-oxo-3-(triethylsilyloxy)-2,4,4,6,8-pentamethyl-7-(2,2,2-trichloroethoxycarbonyloxy)-10-undecenoic acid (11.8 g), tert-butanol (4.5 g), and 4-dimethylaminopyridine (0.2 g) in 20 mL of CH2Cl2 is cooled on ice and treated with dicyclohexylcarbodiimide (4.6 g) over a 5-minute period. The mixture is allowed to warm to ambient temperature and is stirred for 3 hours. The slurry is diluted with CH2Cl2 and filtered, and the filtrate is washed sequentially with sat. aq. citric acid, 5% NaHCO3, and brine. The solution is dried over Na2SO4, filtered, and evaporated. The product is purified by chromatography on SiO2.

Provenance & Evidence