Reaction of some chromens and naphthopyrans with bromine and chlorine. Part V. Preparation of 6,6-disubstituted 4,5-dihydronaphtho(2′,1′:2,3)pyran-5-ones
Abstract
Pyrolysis of the chlorohydrins obtained by ring opening 6,6-disubstituted 4,5-epoxy-4,5-dihydronaphtho(2′1′-2,3)pyrans with hydrogen chloride gave the corresponding 6,6-disubstituted 4,5-dihydronaphtho(2′,1′:2,3)pyran-5-ones.