An improved method for the introduction of carbon-carbontriplebond at C-13 in PG-synthesis is described. The efficient aldol reaction of aldehydes has been achieved by using α-chloro enolate anions derived from 1-bromo-1-chloro ketones, giving α-chloro enones after dehydration in good yields, the precursor of the acetylenic alcohols.
A synthesis of a novel and chemically stable homoisocarbacyclin analog, TY-11223 (3___-), has been accomplished.The analog (3___-), given intravenously or orally, showed potent and long-lasting activities in inhibiting platelet aggregation and, in addition, a good selectivity in biological activities.