反应详情

A suspension of 11.8 g (31.7 mMol) of ethyltriphenylphosphoniumbromide in 64 ml of tetrahydrofuran is treated under stirring and argon atmosphere with 31.9 ml of a one molar solution of potassiumtertiobutylate and the resulting orange suspension treated with a solution of 3.17 g (10.7 mMol) of (4aR,5S,8aS)-5-(tert-Butyl-dimethyl-silanyloxy)-8a-methyl-octahydro-naphtalen-1-one in 64 ml of tetrahydrofuran and kept at room temperature for 3 hours. An additional 11.8 g (31.7 mMol) of ethyltriphenylphosphoniumbromid and 31.9 ml of a one molar solution of potassiumtertiobutylate in tetrahydrofurane are added and the reaction mixture kept overnight. Isobutyraldehyde (5.4 ml) is added, the reaction is stirred for 10 minutes, diluted with diethylether and filtered over Florisil using diethylether as eluent. After evaporation in vacuo, the residue (4.79 g) is chromatographed over 120 g of silica gel with hexane to yield 3.15 g (95%) of pure (1S,4aS,8aR)-tert-Butyl-(5-ethylidene-4a-methyl-decahydro-naphtalen-1-yloxy)-dimethyl-silane (E/Z 4/1) as an oil.

1. additionis treated
2. waitthe reaction mixture kept overnight
3. stirringthe reaction is stirred for 10 minutes
4. filtrationfiltered over Florisil
5. customAfter evaporation in vacuo
6. customthe residue (4.79 g) is chromatographed over 120 g of silica gel with hexane