Dialkyl 1, 3-dithiethan- and 1, 3-dithiolan-2-ylidenemalonate S-oxides have been found to serve as new dienophiles for Diels-Alder reaction with cyclopentadiene. Furthermore, since the adducts thus obtained were transformed to dialkyl 3-oxobicyclo[2.2.1]heptane-2, 2-dicarboxylates, these dienophiles behaved as dialkoxycarbonylketene equivalents.Synthesis of di-l-methyl [1R and 1S]-1, 3-dithiethan-2-ylidenemalonate 1-oxides and their successful use in asymmetric Diels-Alder rections with cyclopentadiene are also described.
研究发现,1, 3-二
硫杂
环丁烷和 1, 3-二
硫杂
环戊烷-2-亚基
丙二酸二烷基 S-氧化物可作为与
环戊二烯进行 Diels-Alder 反应的新亲二烯烃。此外,由于由此获得的加合物被转化为 3-氧代
双环[2.2.1]庚烷-2,2-二
羧酸二烷基酯,这些二烯烃表现为二烷氧基羰基酮当量。