Asymmetric Syntheses of the Homalium Alkaloids (−)-(<i>S</i>,<i>S</i>)-Homaline and (−)-(<i>R</i>,<i>R</i>)-Hopromine
作者:Stephen G. Davies、James A. Lee、Paul M. Roberts、Jeffrey P. Stonehouse、James E. Thomson
DOI:10.1021/jo3012732
日期:2012.8.17
additions of the novel lithium amide reagents lithium (R)-N-(3-chloropropyl)-N-(alpha-methylbenzyl)amide and lithium (R)-N-(3-chloropropyl)-N-(alpha-methyl-p-methoxybenzyl)amide to alpha,beta-unsaturated esters were used as the key steps in syntheses of the homalium alkaloids (-)-(S,S)-homaline and (-)-(R,R)-hopromine. The asymmetric synthesis of (-)-(S,S)-homaline was achieved in 8 steps and 18% overall
新型锂酰胺试剂(R)-N-(3-氯丙基)-N-(α-甲基苄基)酰胺和(R)-N-(3-氯丙基)-N-(α)的高度非对映选择性共轭物-甲基-对甲氧基苄基)酰胺合成α,β-不饱和酯被用作ho生物碱(-)-(S,S)-高马林和(-)-(R,R)-hopromine的关键步骤。(-)-(S,S)-homaline的不对称合成通过8个步骤完成,总产率为18%,(-)-(R,R)-hopromine的不对称合成通过9个步骤和23%实现每种情况下从商业上可获得的原料得到的总收率 因此,迄今为止,这些合成代表了这些生物碱中最有效的总不对称合成。也使用这种方法制备了蛇麻碱的(4'R,4''S)-顶基的样品,