Imidazole → 3beta-Tert-butyldimethylsilyloxy-17beta-(3-furyl)-5beta-androstan-14beta-ol

Participants

Reaction Steps

To a solution of 10 g of 17β-(3-furyl)-5β-androstane-3β,14β-diol (II-a: Ref. comp.) (Minato H. and Nagasaki T., J. Chem. Soc.(C), 1966, 377)in 80 ml of dimethylformamide, 18 g of imidazole and 20.0 g of t-butyldimethylsilyl chloride were added at 0° C. After 12 hrs the mixture was poured into water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and evaporated to dryness under reduced pressure and 15 g of crude 3β-tert-butyldimethylsilyloxy-17β-(3-furyl)-5β-androstan-14β-ol were obtained. A suspension of this protected alcohol and 1.3 g of KH in 75 ml of tetrahydrofuran was heated at 70° C. for an hr; then 2.7 g of methyl iodide were added. After 30' the mixture was poured into water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and evaporated to dryness under reduced pressure to give 12 g of 3β-tert-butyldimethylsilyloxy-14β-methoxy-17β-(3-furyl)-5β-androstane as a white amorphous solid.

Provenance & Evidence