3-Methoxy-, 3, 5-dimethoxy-, and 3-phenyl-4-hydroxyacetophenones suffered alkyl carbonyl C-C bond scission to yield 4-hydroxybenzoate esters and 4-isopropenylphenols under standard conditions of ethylene ketal formati...3-Methoxy-, 3, 5-dimethoxy-, and 3-phenyl-4-hydroxyacetophenones suffered alkyl carbonyl C-C bond scission to yield 4-hydroxybenzoate esters and 4-isopropenylphenols under standard conditions of ethylene ketal formation; the latter underwent in situ dimerization, cyclization, and rearrangement to give substituted indanols. The isopropenylphenol derived from 3,5-ditertbutyl-4-hydroxyacetophenone did not dimerize but condensed with its precursor to yield a substituted diphenylpropanone. 3-nitro-, 3,5-dinitro-, and 3,5-dibromo-4-hydroxyacetophenones on the other hand reacted normally to give ethylene ketals in good yields.展开更多
3-(3,5-Dimethoxybenzyl)-5-hexenoic acid (13) could be cycloacylated by a variant consistion of treating its mixed formate anhydride with tin chloride to give a moderate yield of 3-allyl-6,8-dimethoxy-1-tetralone (24)....3-(3,5-Dimethoxybenzyl)-5-hexenoic acid (13) could be cycloacylated by a variant consistion of treating its mixed formate anhydride with tin chloride to give a moderate yield of 3-allyl-6,8-dimethoxy-1-tetralone (24). Both allyl chains of unsaturated acid 13 and substituted tetralone 24 could be hydroxylated with concentrated sulfuric acid. These results make possible a study of synthesis of some natural perylenequinones and their stereochemistry.展开更多
文摘3-Methoxy-, 3, 5-dimethoxy-, and 3-phenyl-4-hydroxyacetophenones suffered alkyl carbonyl C-C bond scission to yield 4-hydroxybenzoate esters and 4-isopropenylphenols under standard conditions of ethylene ketal formation; the latter underwent in situ dimerization, cyclization, and rearrangement to give substituted indanols. The isopropenylphenol derived from 3,5-ditertbutyl-4-hydroxyacetophenone did not dimerize but condensed with its precursor to yield a substituted diphenylpropanone. 3-nitro-, 3,5-dinitro-, and 3,5-dibromo-4-hydroxyacetophenones on the other hand reacted normally to give ethylene ketals in good yields.
文摘3-(3,5-Dimethoxybenzyl)-5-hexenoic acid (13) could be cycloacylated by a variant consistion of treating its mixed formate anhydride with tin chloride to give a moderate yield of 3-allyl-6,8-dimethoxy-1-tetralone (24). Both allyl chains of unsaturated acid 13 and substituted tetralone 24 could be hydroxylated with concentrated sulfuric acid. These results make possible a study of synthesis of some natural perylenequinones and their stereochemistry.
