Yoshiji Fujita

New sigmatropic sequences based on the [2,3]-wittig rearrangement of the bis-allylic ether system : A general approach to regiocontrolled c—c bond formation of allylic moieties leading to unsaturated carbonyl compounds

Abstract Four new sigmatropic sequences triggered by the regiocontrolled [2,3]-Wittig rearrangement of unsymmetrical bis-allylic ethers (1) to the l,5-dien-3-ols (2) arc described, which provide unique, regiocontrolled methods for the synthesis of a wide variety of unsaturated carbonyl compounds possessing interesting molecular frameworks. The newly developed sequences include the [2,3]-Wittig-Claisen, the tandem [2,3]-Wittig-oxy-Cope, the tandem oxy-Cope-Claisen, and the tandem oxy-Cope-Cope sequences.

Regio- and Stereoselective Oxidation of Ene-Type Chlorinated Olefins

Abstract Regio- and stereoselective oxidation of ene-type chlorinated olefins has been achieved by using potassium 2-propanenitronate as an oxidant and tetrakis(triphenylphosphine)palladium as a catalyst.

Halogen catalyzed acetylenic oxy-cope rearrangement in N-methyl-2-pyrrolidone solvent a new industrial process for pseudoionone and its analogues

Abstract Selective synthesis of pseudoionone was achieved by the acetylenic oxy-Cope rearrangement of 4-isopropenyl-3,7-dimethyl-6-octen-1-yn-3-ol ( 3 ) in N-methyl-2-pyrrolidone solvent containing a trace of hydrochloric acid, hydrobromic acid, iodine, ammonium bromide and ammonium chloride catalysts.

New approach to polyisoprenepolyols possessing glycerol termini by using a highly oxygenated C5-unit

Abstract Polyisoprenepolyols possessing glycerol termini have been synthesized by using 4-(1,2-epoxy-1-methylethyl)-2-phenyl-1,3-dioxolane as a novel highly oxygenated C5-unit.

New diene formation by ene-type chlorination and palladium catalyzed dehydrochlorination: Synthesis of citral from diprenyl ether

Abstract Synthesis of citral from diprenyl ether is achieved by new diene forming reaction which consists of ene-type chlorination and palladium catalyzed dehydrochlorination.

A New Convenient Synthesis of α-Arylpropionic Acid Esters and α-Arylpropionitriles

Abstract Various types of α-arylpropionic acid esters were effectively obtained by the coupling reaction of aryl Grignard reagents and α-bromopropionic acid esters in the presence of nickel catalysts. α-Arylpropionitriles, precursors of α-arylpropionic acids, were also synthesized by the reaction of α-methanesulfonyloxypropionitrile and arylcopper reagents prepared from equimolar amount of arylmagnesium halides and copper(I) bromide.

Selective cleavage of polycyclic cyclopropanes by electrochemical oxidation

Abstract Anodic oxidation in acetic acid of polycyclic cyclopropanes, namely tricyclene, cyclofenchene, and longicyclene, followed by hydrolysis brought about stereo- and regioselective formation of the corresponding homoallylic alcohols as the main product in good yields.

A Convenient Preparative Route to 1,2-Epoxy-3-Methyl-3-Butene Via Ene-Type Chlorination

Abstract 1,2-Epoxy-3-methyl-3-butene has been synthesized from prenyl acetate by using ene-type chlo-rination.

Synthesis of Polyisoprenepolyols Having Multiple Tertiary Hydroxy Moieties Via Hydromagnesation

Abstract Synthesis of polyisoprenepolyols possessing multiple tertiary hydroxy moieties has been achieved efficiently by using hydromagnesation.

Synthesis of Unsaturated Nitriles from Trisubstituted Olefins Via Ene-Type Chlorination

Abstract Unsaturated nitriles have been synthesized from trisubstituted olefins via ene-type chlorination and regioselective substitution with cyanide ion followed by double bond migration.