Takeo Kobori

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 .

A simple total synthesis of cyclopentanoid C9-terpene lactones

The cyclopentanoid C9-terpene lactones, onikulactone (7) and mitsugashiwalactone (8) have been synthesized by a novel intramolecular cyclization of a carbonate ester of cyclopentadienylethanol (2), followed by methylation and hydrogenation.

Photochemical and thermal rearrangement of exo-2,3-epithionorborn-5-ene

2-Thiabicyclo[3,2,1]octa-3,6-diene (2) is obtained by either photochemical or thermal rearrangement of exo-2,3-epithionorborn-5-ene (1), by a stepwise process.