Patent ID: 8846958

Claim:
A process for the synthesis of lubiprostone comprising: a) coupling of cyclopentenone of formula I: with an organocopper compound of formula III: to provide a compound of formula IV: b) reacting the compound of formula IV with hydrogen in the presence of a catalyst to provide a compound of formula V: c) oxidising the compound of formula V to provide a compound of formula VI: d) converting the compound of formula VI to lubiprostone via 1) hydrolysis followed by desilylation or 2) desilylation followed by hydrolysis, wherein R 1 , R 2 , R 3 and Si together form a silyl protecting group, R 13 is nothing, Li(CN), Li 2 (CN)Me, Li 2 (CN) 2 -thienyl, Li(CH═CHCH(OR 17 )CF 2 CH n CH m CH o CH 3 ), or Li 2 (CN)(CH═CHCH(OR 17 )CF 2 CH n CH m CH o CH 3 ), each of n,m and o is 1 or 2 such that either C17 through to C19 is fully saturated or C17 through to C19 contains one single and one double or triple bond, R 16 is a substituted or unsubstituted benzyl protecting group, and R 17 is a substituted or unsubstituted benzyl protecting group.