Substituent Effects in the Reactions of Some Polysubstituted 4-Hydroxy-4-methylcyclohexa-2,5-Dienones With Hydroxide Ion; X-Ray Structure Analyses of 2,5,6-Tribromo-3,4-dihydroxy-4-methylcyclohexa-2,5-dienone and 3,4-Dibromo-5-methyl-5-nitroacetylfuran-2(5H)-one

Abstract

Reactions of the 2,3,5,6-substituted 4-hydroxy-4-methylcyclohexa-2,5-dienones (6a), (6b), (7a) and (7b) with hydroxide ion give 3,4-dihydroxy dienones (9a), (9b), (10) and (11). In contrast, hydroxide ion treatment of the substituted nitro dienone (8), followed by acidification, gives the substituted furan-2(5H)-one (12). The effect of substituents on the course of the reactions is discussed. X-ray structure determinations for compounds (9a) and (12) are reported.