Kazuhiko Sakuma

Regio- and stereo-selective γ-substitution of allylic sulphoxides and sulphones with lithium dialkylcuprates. A new synthesis of trisubstituted olefins

A new regio- and stereo-selective γ-substitution of allylic sulphoxides and sulphones with lithium dialkylcuprates providing a promising new method for the preparation of trisubstituted olefins in particular is described.

New ochtodane syntheses from myrcene

Abstract The ochtodane skeleton is formed stereoselectively from myrcene via acid-catalyzed cyclization of the benzenesulfenyl chloride adduct and that epoxide in a biogenetic type fashion. Its application to the syntheses of two ochtodane-type monoterpenes, an aldehyde component of the boll weevil pheromone and a diol found in the red alga Ochtodes crockeri , is reported.

Regio- and stereo-selective desulphurizative γ-substitution of α-substituted β-methylallyl sulphoxides and sulphones with lithium dialkylcuprates providing trisubstituted olefins

α-Substituted β-methylallyl sulphoxides (2) and sulphones (3) undergo regio- and stereo-selective desulphurizative γ-substitution by the action of lithium dialkylcuprates in ether. The reaction provides a new method for the synthesis of trisubstituted E-olefins E-(4).

Facile regio- and stereo-specific allylic oxidation of gem-dimethyl olefins via addition of benzenesulphenyl chloride. Synthesis of allylic oxygenated terpenes

Novel and facile terminal trans-allylic and internal allylic oxidations of the gem-dimethyl olefin terminus of the terpenoids (1) are described which take place site-, regio-, and stereo-specificially via the same intermediate adduct between benzenesulphenyl chloride and (1). By this method, the allylic oxygenated terpenes (±)-nuciferal (11), (±)-ar-turmerone (12), (±)-ipsdienol (3c), neotorreyol (2e), (±)-6-hydroxydendrolasin (3e), and 6-oxodendrolasin (14) were synthesized.