Tatsuo Kawara

A stereocontrolled total synthesis of optically active (R,R)-phytol

A stereospecific synthesis of (R,R)-phytol uith highly stereochemioal purity in both absolute and geometrical aonfigurations uas achieved by utilizing the SNZ type ring-opening reaction of (R)-β-methyl-β-propiolactone, and the SNZ′ type ring-opening reaction of isopropenyl oxirane, from (R)-pulegone as a starting material.

A novel synthetic method for optically active terpenes by the ring-opening reaction of (R)-(+)-β-methyl-β-propiolactone

Abstract Optically active terpene such as ( R )-(+)-citronellol, ( R )-(+)-pulegone or ( S )-ar-turmerone is prepared in high enantiomeric excess from an intermediate, ( R )-(+)-citronellic acid or ( S )-(+)-3-p-tolylbutyric acid, which is easily prepared by the S n 2 type of ring opening reaction of ( R )-(+)-β-methyl-β-propiolactone with homoprenylmagnesium bromide in the presence of a copper(I) salt or di-p-tolylcuprate.

A three carbon homologation by the ring-opening of β-propiolactones with diorganocuprates

Abstract Various organocuprates react with β-propiolactones to give β-substituted propionic acids in high yields.

A novel synthesis of (E)-3,7-dimethyl-2-octene-1,8-diol secreted by the african monarch using the ring-opening reaction of α-methyl-β-propiolactone

Abstract The regioselective ring-opening reaction of α-methyl-β-propiolactone with 3,3-ethylene-dioxybutylmagnesium bromide in the presence of copper(I) catalyst afforded 2-methyl-6-oxoheptanoic acid, which was easily converted into (E)-3,7-dimethyl-2-2-octene-1,8-diol in good yield.

A novel method for the terpene synthesis by the ring-opening reaction of β-methyl-β-propiolactone

Abstract A new route for the terpene synthesis is investigated, which undergoes via terpene carboxylic acids as key intermediates obtained by the regiospecific ring opening of β-methyl-β-propiolactone with a cuprate or with a Grignard reagent in the presence of a copper catalyst.