On the mechanism of the Leuckart reaction. Enantiospecific preparation of (1R,2R)- and (1S,2S)-N-(3,3-dimethyl-2-formylamino-1-norbornyl)acetamide
作者:A Garcı́a Martı́nez、E Teso Vilar、A Garcı́a Fraile、P Martı́nez Ruiz、R Macı́as San Antonio、M.P Martı́nez Alcázar
DOI:10.1016/s0957-4166(99)00125-1
日期:1999.4
The Leuckart reaction of 2-norbornanone and (1R)-N-(3,3-dimethyl-2-oxo-1-norbornyl)acetamide ent-1b furnishes the expected N-(2-norbornyl)formamides 11 and ent-10 in good yield. Surprisingly, under the same reaction conditions, the (1R)-N-(7,7-dimethyl-2-oxo-1-norbornyl)acetamide 1a gives only 10, the enantiomeric form of the product obtained from ent-1b. An explanation of these results is given and
2- norbornanone的洛伊卡特反应和(1 - [R )- ñ - (3,3-二甲基-2-氧代-1-降冰片基)乙酰胺ENT - 1B配料预期Ñ - (2-降冰片基)甲酰胺11和ENT - 10产量高。出人意料的是,在相同的反应条件下,将(1 - [R )- ñ - (7,7-二甲基-2-氧代-1-降冰片基)乙酰胺1A仅给出10,从所获得的产物的对映体形式ENT - 1B。给出了这些结果的解释,并提出了一种基于前所未有的分子内氨基转移的反应机理。