11,21-DIACETATE (22RS)-16α,17α-BUTYLIDENEDIOXY-1111β, 21-DIHYDROXYPREGNA-1,4-DIENE-3,20-DIONE AS INTERMEDIATE PRODUCT IN SYNTHESIS OF BUDECONIDE Russian patent published in 1994 - IPC

FIELD: steroid compounds, more particularly (22RS-16α; 17α-butylidenedioxy-11β, 21-dihydroxypregna-1,4-diene-3.20-dione 11,21-diacetate as an intermediate product in the synthesis of budeconide. SUBSTANCE: the semifinished product is synthesized by acetalization of 16α-oxyprednisolone 11.21-diacetate with butyric aldehyde in a CH₂Cl₂ solution in the presence of a HClO₄ catalyst. The yield 96.5%, mp 118-128 C after decrystallization 150-160 C; [α]2D

⁰= + 108°, the empirical formula 1: C₂₉H₃₈O₈. The new semifinished product makes it possible to obtain industrial budeconide by a microbiological method (using the culture coryn mediolanum( with a yield of 100%; after the purification the yield 70%, and the total yield as calculated for prednisolone about 43%; this is by 2 times higher than in the prior art. EFFECT: a new semifinished product for the synthesis of effective broncholitic with high yield.