Acid-Promoted Retro-Mannich Reaction ofN-Protected Tropenones to 2-Substituted Pyrroles
作者:Nicolai Cramer、Jeannette Juretschke、Sabine Laschat、Angelika Baro、Wolfgang Frey
DOI:10.1002/ejoc.200300804
日期:2004.4
N-protected tropenone undergoes highly regioselective retro-Mannich reactions to 2-pyrrolyl ketones in the presence of Lewis or Bronsted acids. Analogously, a pyrrole deriv. was obtained by using subsequent nucleophilic trapping with trimethylsilanecarbonitrile. The possible Grob fragmentation of 3-oxo-8-azabicyclo[3.2.1]oct-6-ene-8-carboxylates and 8-[(4-methylphenyl)sulfonyl]-8-azabicyclo[3.2.1]oct-6-en-3-one
在路易斯酸或布朗斯台德酸的存在下,N-保护的 tropenone 对 2-吡咯基酮进行高度区域选择性的逆曼尼希反应。类似地,吡咯衍生物。通过随后使用三甲基硅烷甲腈进行亲核捕集获得。3-oxo-8-azabicyclo[3.2.1]oct-6-ene-8-carboxylates 和 8-[(4-methylphenyl)sulfonyl]-8-azabicyclo[3.2.1]oct-6- 可能的 Grob 碎裂还研究了 en-3-one。3-氧代-8-氮杂双环[3.2.1]oct-6-ene-8-羧酸Me酯(I)在4-甲基苯磺酸存在下的逆曼尼希反应得到2-(2-氧代丙基)- 1H-吡咯-1-羧酸Me酯(II)。