20-(5,5-Dimethyl-1,3-dioxan-2-yl)-1alpha,2alpha-epoxy-7alpha-methoxycarbonyloxypregn-5-en-3beta-yl acetate → 20-(1,3-Dioxolan-2-yl)-1alpha,2alpha-epoxypregna-5,7-dien-3beta-yl acetate

Participants

Reaction Steps

The procedure of Example 17 was repeated except that 40.2 mg (0.0798 mmole) of 20-(1,3-dioxolan-2-yl)-1α,2α-epoxy-7α-methoxycarbonyloxypregn-5-en-3β-yl acetate was used in lieu of 43.6 mg of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxy-7α-methoxycarbonyloxypregn-5-en-3β-yl acetate to give 15.5 mg of 20-(1,3-dioxolan-2-yl)-1α,2α-epoxypregna-5,7-dien-3β-yl acetate. In addition, 14.2 mg of the starting compound 20-(1,3-dioxolan-2-yl)-1α,2α-epoxy-7α-methoxycarbonyloxypregn-5-en-3β-yl acetate was recovered. The yield of 20-(1,3-dioxolan-2-yl)-1α,2α-epoxypregna-5,7-dien-3β-yl acetate was 70% based on consumed 20-(1,3-dioxolan-2-yl)-1α,2α-epoxy-7α-methoxycarbonyloxypregn-5-en-3β-yl acetate.

Provenance & Evidence