Tetrahydropyran Synthesis by Intramolecular Conjugate Addition to Enones: Synthesis of the Clavosolide Tetrahydropyran Ring
作者:Roderick Bates、Ping Song
DOI:10.1055/s-0030-1257890
日期:2010.9
The synthesis of a tetrahydropyran intermediate for clavosolide A is reported, employing a combination of cross-metathesis and intramolecular oxa-Michael addition. The intramolecular oxa-Michael addition to α,β-unsaturated esters requires the use of strong bases and can result in either modest yields or stereoisomeric mixtures, and can be highly variable according to the substrate structure. In contrast
据报道,通过交叉复分解和分子内的氧杂-迈克尔加成反应,合成了用于clavosolide A的四氢吡喃中间体。α,β-不饱和酯的分子内oxa-Michael加成需要使用强碱,并可能导致适度的收率或立体异构体混合物,并且根据底物结构可能存在很大差异。相反,相应的酮在非常温和的条件下环化,直接得到2,6-顺式异构体。使用适当取代的酮可以有效地转化成酯。 迈克尔加成-串联反应-环化