Boron trifluoride → HCID 86733307, compound

Participants

Reaction Steps

2α,3α-Epoxy-5α-pregnane-11,20-dione (450 mg.) in dry ether (4 ml.) and thioacetic acid (1 ml.) was treated with BF3 etherate (2 drops). The resulting yellow solution was stirred at room temperature for 20 minutes. The solution was partitioned between ethyl acetate (20 ml.) and water (20 ml.) and the aqueous layer was extracted with more ethyl acetate (20 ml.). The combined organic extracts were washed with water (2 × 20 ml.) and dried over sodium sulphate and evaporated to a yellow oil which was purified by preparative t.l.c., in ethyl acetate/petroleum ether (1:1) to give the title compound as a pale yellow foam. [α]D + 93° (c 0.56); Rf 0.15; N.M.R.:-7.65τ (CH3COS--); 6.16τ (2-- and 3--H).

Provenance & Evidence