On the reaction of diazomethane with 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone. Formation and crystal structure analysis of 2,5-Diacetoxy-3,4-dichlorocyclohepta-1,3,5-triene-1,6-dicarbonitrile

Abstract

The structure of a compound previously believed to be the diacetate of 2,3-dichloro-5,6-dicyano-4- hydroxybenzyl alcohol has been analysed by X-ray methods and found to be that of the isomeric 2,5-diacetoxy-3,4-dichlorocyclohepta-1,3,5-triene-1,6-dicarbonitrile. Consequently, the product formed in the reaction of diazomethane with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (ddq), earlier thought to be an oxirano-substituted cyclohexa-2,5-dienone, is 3,4-dichloro-2,5-dioxobicyclo-[4,1,0]hept-3-ene-1,6-dicarbonitrile.