Regioselective and enantiospecific synthesis of 6-substituted and 5,6-disubstituted hexahydropyrimidines
作者:Peter J. Garratt、Simon N. Thorn、Roger Wrigglesworth
DOI:10.1016/s0040-4039(00)74861-1
日期:1991.1
The preference for 5- over 6-membered rings in the intramolecular cyclisation of amines with diesters can be partially overcome with mixed methyl (or benzyl), tert-butyl diesters, and this effect is enhanced where there is a β-substituent. The hexalhydropyrimidines are formed enantiospecifically, the amount of racemization usually being less with a β-substituent present.
用混合的甲基(或苄基)叔丁基二酯可以部分克服胺与二酯的分子内环化反应中5元环或6元环的偏爱,这种作用在存在β取代基的情况下得到了增强。六氢嘧啶是对映体特异性形成的,在存在β-取代基的情况下,外消旋化的量通常较少。