Imidazole → (4aR,5S,8aS)-5-(tert-Butyl-dimethyl-silanyloxy)-8a-methyl-octahydro-naphtalen-1-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 2.3 g (12.6 mMol) of (4aR,5S,8aS)-5-hydroxy-8a-methyl-octahydro-naphtalen-1-one in 63 ml of dimethylformamide are added under stirring and argon atmosphere 3.74 g (24.8 mMol) of tertio-butyl-dimethyl-silylchloride and 1.94 g (28.5 mMol) of imidazole. The reaction mixture is heated to 100° C. for 4 hours, then additional 3.74 g of tert-butyl-dimethylsilylchloride and 1.94 g of imidazole are added and the reaction mixture is kept overnight at 100° C. The reaction mixture is poured onto ice-water and extracted three times with diethylether. The combined organic extract is washed once with water and brine, dried over sodium sulfate and evaporated in vacuo. The residue is chromatographed over 250 g of silicagel with hexane/ethylacetate 9/1 to yield 3.17 g (85%) of low melting cristalline (4aR,5S,8aS)-5-(tert-butyl-dimethyl-silanyloxy)-8a-methyl-octahydro-naphtalen-1-one.

Provenance & Evidence