Seizi Kurozumi

A short synthesis of (−)-prostaglandin E1

Abstract (−)-Prostaglandin E1 has been prepared from ( R -4- t -butyldimethylsiloxy-2-cyclopentenone by using as a key operation the tandem organocopper conjguate addition/nitroolefin Michael trapping of the resulting enolate intermediate.

Palladium-catalyzed coupling reactions of bromobenzaldehydes with 3,4-di(tert-butyldimethylsilyloxy)-1-alkene to (3,4-dihydroxyalkenyl)benzaldehydes in the synthesis of lipoxin analogues

o-, m-, and p-(3,4-Dihydroxyalkenyl)benzaldehydes were selectively prepared via palladium-catalyzed Heck-type coupling reactions of o-, m-, and p-bromobenzaldehydes with 3,4-di(tert-butyldimethylsilyloxy)-1-alkene. The products were employed for the synthesis of lipoxin analogues, o-, m-, and p-3-hydroxyalkenyl-3,4-dihydroxyalkenylbenzenes.

Short synthesis of 6-oxoprostaglandin E1 and 6-oxoprostaglandin F1α

Abstract 6-Oxoprostaglandin E1 methyl ester was synthesized in a single pot from ( R )-4- t -butyldimethylsiloxy-2-cyclopentenone by organocopper conjugate addition with an ω side-chain unit, trapping of the resulting enolate with 6-methoxycarbonyl-2-nitrohex-1-ene, and treatment with aqueous titanium(III) trichloride. Hydrolysis of the methyl ester was accomplished by porcine liver esterase. 6-Oxoprostaglandin F1α, was obtained from 6-nitroprostaglandin E1 methyl ester in four steps.

Stereospecific synthesis of (5E)-PGE2 by palladium-catalyzed decarboxylative 2-alkenylation of 2-alkenyloxycarbonylated cyclopentanone derivative

(5E)-Prostaglandin E2 methyl ester was synthesized from (R)-4-t-butyldimethylsiloxy-2-cyclopentenone by in situ 2-alkenyloxycarbonylation of the organocopper conjugate-addition adduct followed by intramolecular palladium-catalyzed decarboxylative 2-alkenylation. A (E)-2-butenylated cyclopentanone derivative was obtained from either 2-[(E)- or (Z)-2-butenyloxy-carbonyl]cyclopentanone derivative under the similar reaction condition.