On the regioselectivity in nitrone cycloadditions to γ-oxo α,β-unsaturated esters
作者:Ramón Alibés、Félix Busqué、Pedro de March、Marta Figueredo、Josep Font、Teodor Parella
DOI:10.1016/s0040-4020(98)00628-0
日期:1998.9
The 1,3-dipolar cycloadditions of the cyclic nitrones 1 and 2 to several γ-oxo α,β-unsaturated esters, 5–10, are reported. A strong predominance of the regioisomers with the oxygen atom of the dipole attached to the β-ester position is observed. This high regioselectivity is attributed to steric factors. The reduction of the carbonyl group of some of the major cycloadducts is a good yielding procedure
据报道,环状硝酮1和2的1,3-偶极环加成有几种γ-氧代α,β-不饱和酯5-10。观察到区域异构体的强烈优势是偶极子的氧原子附着在β-酯位置上。这种高区域选择性归因于空间因素。某些主要环加合物的羰基还原是制备某些羟基衍生物的好方法,这些羟基衍生物在相同硝酮与相应的γ-羟基α,β的环加成中并未形成或仅以较小的立体异构体形式获得。 -不饱和酯。