Dimethyl Carbonate → 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1alpha-(tert-butyldimethylsilyl)oxy-3beta-(N,N-dimethylcarbamoyl)oxy-7alpha-(methoxycarbonyl)oxypregn-5-ene

Participants

Reaction Steps

In 10 ml of dimethyl carbonate was dissolved 350 mg of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α-(tert-butyldimethylsilyl)oxy-3β-(N,N-dimethylcarbamoyl)oxypregn-6-en-5α-ol, followed by addition of one drop of concentrated sulfuric acid. The mixture was stirred in an atmosphere of argon gas under ice-cooling for 1 hour. The reaction mixture was then worked up in the same manner as Example 132 to give 95 mg of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α -(tert-butyldimethylsilyl)oxy-3β-(N,N-dimethylcarbamoyl)oxy-7α-(methoxycarbonyl)oxypregn-5-ene showing the following physical properties.

Provenance & Evidence