Diels–Alder Reactions with Cyclic Sulfones: VII. Synthesis of 1-Benzothiophene 1,1-Dioxide Derivatives
作者:G. N. Andreev、E. E. Shul’ts、A. A. Volkov、M. M. Shakirov、I. Yu. Bagryanskaya、Yu. V. Gatilov、G. A. Tolstikov
DOI:10.1023/b:rujo.0000044549.81561.4f
日期:2004.6
5-Arylmethylene-2,2-dimethyl-1,3-dioxane-4,6-diones reacted with 5-isopropenyl-2,3-dihydrothiophene 1,1-dioxide to give the corresponding ortho-addition products, 5-aryl-2',2',7-trimethyl-3,3a,5,6-tetrahydro-2H-spiro[1-benzothiophene-4,5'-[1,3]dioxane]-4',6'-dione 1,1-dioxides. Their aminolysis resulted in opening of the 1,3-dioxane ring and formation of 4-carbamoyl-7-methyl-2,3,3a,4,5,6-hexahydro-l-benzothiophene-4-carboxylic acid 1,1-dioxide whose structure was determined by X-ray analysis. Reactions of the spiro adducts with amines and hydrazine hydrate afforded the corresponding mono- or dicarboxylic acid monoamides (hydrazide).