Novel synthesis of 3H-pyrroles, and novel intermediates in the Paal–Knorr 1H-pyrrole synthesis: 2-hydroxy-3,4-dihydro-2H-pyrroles from 1,4-diketones and liquid ammonia
作者:Pak-Kan Chiu、Kon-Hung Lui、Prem Nath Maini、Michael P. Sammes
DOI:10.1039/c39870000109
日期:——
2-dimethyl-1,4-diketones with liquid ammonia gives high yields of isolable 2-hydroxy-3,4-dihydro-2H-pyrroles (3) and (5) which are readily dehydrated to give separable mixtures of 3H-pyrroles and methylenedihydropyrroles, while less-substituted 1,4-diketones give analogous hydroxy-compounds (4) and (6) which are hitherto-unsuspected intermediates in the Paal–Knorr 1H-pyrrole synthesis.
2,2-二甲基-1,4-二酮与液氨的反应得到高产率的可分离的2-羟基-3,4-二氢-2 H-吡咯(3)和(5),它们很容易脱水以得到可分离的混合物3 H-吡咯和亚甲基二氢吡咯中,较少取代的1,4-二酮产生类似的羟基化合物(4)和(6),是Paal–Knorr 1 H-吡咯合成中迄今未曾怀疑的中间体。