Sodium hydride → HCID 67301139, compound

Participants

Reaction Steps

1α,3β-Bis(tert-butyldimethylsilyloxy)-20(R)-hydroxypregna-5,7,16-triene (158 mg, 0.283 mmol) was treated with sodium hydride (60% in oil, 77 mg, 1.925 mmol), tetrahydrofuran (6 ml), 15-crown-5 (67 mg, 0.304 mmol) and t-butyl bromoacetate (0.25 ml, 1.679 mmol) in the same manner as shown in Example 8(1) (at an external temperature of 85° C. for 11 hours and 40 minutes) and then worked up. The resulting residue was purified by column chromatography (hexane:ethyl acetate=10:1) and preparative thin layer chromatography (0.5 mm×3 plates, hexane:ethyl acetate=20:1, developed twice) to give the titled compound (142.6 mg, 75%) as a colorless oil.

Provenance & Evidence