A New Procedure for the Preparation of β-Keto-δ-lactones from Sugars and Their Transformation into Glycosyl Acceptors in Disaccharides Synthesis
作者:Alessandra Bartolozzi、Giuseppe Capozzi、Stefano Menichetti、Cristina Nativi
DOI:10.1021/ol991176c
日期:2000.2.1
materials for the synthesis of enantiopure beta-ketone-delta-lactones. They are easily transformed, through a two-step, one-pot reaction, into the corresponding alpha,alpha'-dioxothiones which in turn can be quantitatively trapped with dienophiles in inverse electron-demand [4 + 2] cycloadditions. The reaction of dioxothione 8b with endo and exo glucals allowed the elaboration of a new protocol to prepare
[反应:见正文]乙二醇是合成对映纯β-酮-δ-内酯的有效起始原料。通过两步一锅反应,它们很容易转化为相应的α,α'-二氧噻吩硫酮,而后者又可以被反电子需求的[4 + 2]环加成中的亲二烯体定量捕集。二氧噻硫酮8b与内和外葡糖的反应允许拟订新的方案以立体选择性地制备2-硫代-或2-脱氧二糖。