1,5-Diazabicyclo(4.3.0)non-5-ene → HCID 10782414, compound

Participants

Reaction Conditions

Reaction Steps

1740 mg of (S)-2-[(1R,3aR,4S,7aR)-4-(tert-butyl-dimethylsilanyloxy)-7a-methyl-octahydro-inden-1-yl]-propan-1-al was dissolved in anhydrous THF (35 ml). DBN (640 ml; 5,36 mmol) was added and the mixture was refluxed for four hours. The reaction mixture, after cooling, was poured in cold citric acid solution, extracted with ethyl-acetate, washed with brine and dried over Na2 SO4. Removal of the solvent afforded a crude colourless oil (approximately 1:1 mixture at C(20)). The crude mixture was then dissolved in isopropanol (40 ml), cooled to 0° C., and NaBH4 (232 mg; 6,13 mmol) was added. The cooling bath was removed and stirring was continued for half an hour at room temperature. The reaction mixture was poured in cold brine, extracted with ethyl-acetate, dried over Na2 SO4. Removal of the solvent afforded a colourless oil. HPLC chromatography (eluent: n-hexane/ethyl-acetate 85:15) allowed the separation of both diastereoisomers affording 887 mg (50,7%) of the desired (R)-2-[(1R,3aR,4S,7aR)-4-(tert-Butyl-dimethyl-silanyloxy)-7a-methyl-octahydro-inden-1-yl]-propan-1-ol as a colourless oil.

Provenance & Evidence