Diastereoselective Yang Photocyclization Reactions in Solution. Synthesis of Enantiopure Azetidin-3-ol Derivatives
作者:Rafael Pedrosa、Celia Andrés、Javier Nieto、Soledad del Pozo
DOI:10.1021/jo0481497
日期:2005.2.1
Chiral 2-acyl-3-allyl- or 2-acyl-3-benzyl-substituted perhydro-1,3-benzoxazines readily cyclized under irradiation to azetidin-3-ol derivatives. The diastereoselectivity of the cyclization is dependent on the nature of the substituents at the nitrogen atom. N-allyl-substituted derivatives yielded only two of the four possible diastereomers in moderate to good diastereomeric excess. The cyclization
手性2-酰基-3-烯丙基或2-酰基-3-苄基取代的过氢-1,3-苯并恶嗪在辐射下易于环化成氮杂环丁烷-3-醇衍生物。环化的非对映选择性取决于氮原子上取代基的性质。N-烯丙基取代的衍生物仅产生中度到良好的非对映异构体过量的四种可能的非对映异构体中的两种。N-苄基衍生物的环化是完全非对映选择性的,从而导致单个非对映异构体。薄荷脑附件的消除导致对映体纯的2,3-二取代的氮杂环丁烷-3-醇衍生物。