Kunikazu Sakai

Novel cyclopentenonyl fatty acids from mosses, dicranum scoporium and dicranum japonicum

Abstract The novel cyclopentenonyl fatty acids, dicranenone A (III) and dicranenone B1 (IV), were isolated from Japanese mosses.

Total synthesis of (±)-dicranenones, novel cyclopentenonyl fatty acids

Abstract Dicranenones 1 and 2 have been synthesized from the intermediate 12, which was either derived from methyl jasmonate 7 or prepared by the intramolecular ring formation of diazo compound 14.

A new selective dichlorination of CC double bonds

Abstract A new dichlorination procedure of CC double bond was developed with hexachloroethane as chlorinating agent and RuCl2(PPh3)3 as catalyst. The reaction is highly selective for CC double bond; other functional groups are unaffected by these conditions.

Prostaglandin synthesis from a fulvene with the ω-side chain equivalent

Abstract The acid-catalyzed hydrolysis of the Diels-Alder adduct of 6-(2,2-ethylene-dioxyheptyl) fulvene with 2-chloroacrylonitrile gave 7-anti-(3-oxo-1-trans-octenyl)-2-chloro-2-cyanobicyclo[2.2.1]hept-5-ene, which is an intermediate of 12-epi-prostaglandine. On the other hand, the hydrolysis of 7-(3,3-ethylenedioxyoctylidene)bicyclo-[2.2.1]hept-5-en-2-one, obtained from the Diels-Alder adduct of the fulvene with 2-chloroacryloyl chloride, gave a mixture (3:2) of 7-anti- and 7-syn-(3-oxo-1-trans-octenyl)bicyclo[2.2.1]hept-5-en-2-one. The latter compound was oonverted into prostaglandin F 2α .