Asymmetric syntheses of 3,4-syn- and 3,4-anti-3-substituted-4-aminopiperidin-2-ones: application to the asymmetric synthesis of (+)-(3S,4R)-cisapride
作者:Stephen G. Davies、Rosemary Huckvale、James A. Lee、Thomas J.A. Lorkin、Paul M. Roberts、James E. Thomson
DOI:10.1016/j.tet.2011.12.084
日期:2012.4
gives the corresponding 3,4-syn-3-hydroxy-4-aminopiperidin-2-ones in >99:1 dr. The utility of this methodology was successfully demonstrated in a concise asymmetric synthesis of the gastroprokinetic agent (+)-(3S,4R)-cisapride (+)-(3S,4R)-N(1)-[3′-(4″-fluorophenoxy)propyl]-3-methoxy-4-(2‴-methoxy-4‴-amino-5‴-chlorobenzamido)piperidine} in nine steps from commercially available starting materials with
将(R)-N-苄基-N-(α-甲基苄基)酰胺共轭加成到δ-(N-烯丙基氨基)-α,β-不饱和酯中,然后N-去烯丙基化并环化所得的β,δ -二氨基酯,得到相应的4-氨基哌啶-2-酮,为单一非对映异构体(> 99:1 dr)。随后用LiHMDS脱质子化,并将所得的烯醇锂官能化,得到3,4-抗-3-取代-4-氨基哌啶-2-酮的> 99:1 dr。或者,在共轭加成后形成的中间锂(Z)-β-氨基烯醇盐的原位氧化得到α-羟基-β,δ-二氨基酯,经N-去烯丙基化和环化后得到相应的3,4- syn> 99:1博士中的-3-羟基-4-氨基哌啶-2-酮 该方法的效用是成功地证明在gastroprokinetic剂(+)的简明不对称合成- (3-小号,4 - [R)-cisapride (+) - (3小号,4 - [R )- Ñ(1) - [3-从商业上可得的起始原料,以九步法制备′-(4″-氟苯氧基)丙基]