Ethyl 3-alkyl-3-hydroxy-5-nitro-2, 3-dihydro-2-benzofurancarboxylates were obtained from the reaction of ethyl 2-acyl-4-nitrophenoxyacetates with potassium hydroxide in dry dioxane. The relative ratios of the cis and trans isomers with respect to C-2 and C-3 stereochemistry varied according to the structure of the acyl group. When the acyl group was acetyl, propionyl, or isobutyryl group, the cis isomers (2-alkoxycarbonyl groups and 3-hydroxyl ...