A kind of method from sterol fermented product synthesis difluprednate

The invention provides a kind of method from sterol fermented product synthesis difluprednate.Sterol fermented product 9 Alpha-hydroxies-androstane-1 that the plant sterol very enriched with content in oil prodution industry byproduct ferments and comes, 4-diene-3, 17-diketone (9 α-OH-AD) is starting raw material, experience steroidal 9 hydroxyls dehydrate become double bond, 17 carbonyls add acetylene, dehydration, acid lower generation 21 ketone carbonyls, 16, 17 double bond epoxidations, periodide oxidation introducing 21 hydroxyls, 16, the open loop of 17 α epoxide hydroformylation bromic acids, 16 β bromine hydrogenations remove, become cyclic orthoesters, open loop, ester, 9, 11 double bond β epoxidations, enolization esterification, 6 electric fluoro of parent and 9, 11 epoxy fluoro open loops, totally 15 step reactions.Periodide is utilized to be oxidized and epoxy addition, debrominate efficiently construct steroidal 17 α, 21-dihydroxyl, obtain important intermediate formula 11 compound, whole process effectively prevent the plurality of heavy metal pollutent chromium that traditional industry production corticosteroids medicine produces, and environmental protection is applicable to suitability for industrialized production.