Patent ID: 7166730
Filing Date: 2007-01-23
Classification: C07C,C07D

Abstract:
1. A process for the preparation of alkyl 5Z-prostenoates of formula [1] wherein R is 3-CF 3 C 6 H 4 O—, 3-ClC 6 H 4 O—, PhO—, Bn—, Bu—, Me(CH 2 ) 5 —; A is —CH 2 CH 2 — or —CH═CH—; X is X 1 , O or (α-OH, H); X 1 is (α-OR 3 , H), —OCH 2 CH 2 O—; (F, F); R 1 is C 1 –C 10 alkyl group; R 3 is selected from the group consisting of trialkylsilyl, dialkylarylsilyl, 1-alkoxyalkyl, unsubstituted and alkyl-substituted tetrahydro-2H-pyran-2-yl and tetrahydrofuran-2-yl group; α is down; such process comprising: (a) contacting Corey aldehyde of formula [7] wherein R wherein R (b) converting the compound of formula [6] prepared at the step (a), to compound of formula [5] wherein X (c) reducing the compound [5] with diisobutylaluminum hydride at a temperature range from −30 to 0° C. to give the compound [4] wherein A, R and X (d) reacting compound [4] with a metal salt of 5-(triphenylphosphoranylidene)pentanoic acid, to obtain the 5Z-prostenoic acid of formula [3] wherein A, R and X are as defined above; (e) converting 5Z-prostenoic acid [3] to cesium 5Z-prostenoate of formula [2] wherein A, R and X are as defined above; and (f) esterifying the cesium 5Z-prostenoate [2] with compound R wherein Y is a leaving group and R