Photodechlorination of the diels-alder adduct of 1,4-Dihydro-1,4-epoxynaphtalene and 1,2,3,4-Tetrachloro-5,5-dimethoxycyclopentadiene

Abstract

Ultraviolet irradiation in ether of the Diels-Alder adduct, (1), of 1,4-dihydro-1,4-epoxynaphthalene and 1,2,3,4-tetrachloro-5,5-dimethoxycyclopentadiene, gave 1,2,4-trichloro-ll ,ll-dimethoxy-1,4,9,-9a,10,10a-hexahydro-9,10-epoxy-1,4-methanoantacene (2) and 1,2,3-trichloro-ll,ll-dimethoxy-1,4,9,9a,10,10a-hexahydro-9,10-epoxy-1,4-methanoanthracene (3) as the main products. The formation of (3) represents a new photochemical pathway in these chlorinated polycyclic systems.