Radical cyclizations on sugar templates: Stereoselective synthesis of fused γ-butyrolactones of carbohydrates
作者:Sonsoles Velázquez、María-José Camarasa
DOI:10.1016/s0957-4166(00)86290-4
日期:1994.11
A stereoselective method is described for the synthesis of [3.3.0] fused lactones (γ-butyrolactones) of carbohydrates at the 2 and 3 positions of the furanose ring, by intramolecular addition of radicals onto the α-position of α,β-unsaturated esters. A new stereogenic center is formed at an off-template site of the ribofuranose ring, with good diastereoselectivity. Stereocontrol is discussed on the
描述了一种立体选择性方法,用于通过在呋喃糖环的2和3位上分子内加成自由基到α,β-不饱和的α-位上来合成碳水化合物的[3.3.0]稠合内酯(γ-丁内酯)酯。在核呋喃呋喃糖环的模板外位点形成了一个新的立体异构中心,具有良好的非对映选择性。在过渡态的构象偏好基础上讨论了立体控制。这些碳水化合物的γ-丁内酯可用于制备支链糖。内酯环的打开提供了在C-2或C-3处具有高度官能化的C-分支的同手性支链糖。