Reductive Cyclizations of Hydroxysulfinyl Ketones: Enantioselective Access to Tetrahydropyran and Tetrahydrofuran Derivatives
作者:M. Carmen Carreño、Renaud Des Mazery、Antonio Urbano、Françoise Colobert、Guy Solladié
DOI:10.1021/jo034817x
日期:2003.10.1
The stereocontrolled formation of cis-2,5-disubstituted tetrahydrofurans and cis-2,6-disubstituted tetrahydropyrans is achieved from enantiopure ketosulfinyl esters by reduction, Weinreb's amide, and ketone formation, followed by the reductive cyclization (Et3SiH/TMSOTf) of the resulting hydroxysulfinyl ketones. The sulfoxide-bearing heterocycles were transformed into two natural products, (-)-centrolobine
通过还原,Weinreb酰胺和酮的形成,从对映体纯的酮亚磺酰基酯中实现顺式2,5-二取代的四氢呋喃和顺式2,6-二取代的四氢吡喃的立体控制形成,然后将所得产物进行还原环化(Et3SiH / TMSOTf)。羟基亚磺酰基酮。带有亚砜的杂环被转化为两个天然产物,(-)-中心叶氨酸(1)和两个顺式-(6-甲基四氢吡喃-2-基)乙酸的对映体(2)。