Kiyotaka Ohno

Organic synthesis by means of noble metal complexes—XCIV : Palladium catalyzed hydrosilylation of monoenes and conjugated dienes

Abstract Palladium compounds and metallic palladium combined with phosphine are active catalysts of selective hydrosilylation of terminal olefins. Butadiene and trichlorosilane give a 1:1 adduct and trimethylsilane affords a 1:2 adduct. Special features of the palladium catalyzed hydrosilylation reactions are presented.

A mild methylation of alcohols with diazomethane catalyzed by silica gel

Abstract Alcohols including prostaglandins, geraniol, and carbohydrate, can easily be methylated with diazomethane in the presence of silica gel.

Organic syntheses by means of noble metal compounds—XLVII : Reaction of butadiene with aldehydes and ketones catalyzed by palladium-phosphine complexes

Abstract Palladium catalyzed reaction of butadiene with carbonyl compounds yields 1-substituted 2-vinyl-4, 6-heptadien—1-ols or 2-substituted 3,6-divinyltetrahydropyrans. Four stereoisomeric pyrans were characterized by NMR analysis. The reaction mechanism is discussed.

Synthesis of (±)-5,6,7-trinor-4,8-inter--phenylene PGI2

A stable and potent analog of prostacyclin, the titled compound, and its derivative were synthesized from readily available 1,4-dibromocyclopentene via 5-(4-tetrahydropyranyloxybutyl) cyclopenta [b] benzofuran

4,5,6,7-tetradehyro-PG1, a stable and potent inhibitor of blood platelet aggregation

The titled compound, which is a stable and potent analog of PGI2, was synthesized from easily available enone 3 in two steps.

Synthesis of 6,7-dehydro-5-oxo-prostaglandin I1: A stable analog of prostacyclin

Abstract Stable analogs of prostacyclin, 6,7-dehydro-5-oxo-prostaglandin I 1 and derivatives, were synthesized from readily available 6,7-dehydro-5-hydroxy-prostaglandin F 1α methyl ester 2