Synthesis of 7-Deoxypancratistatin from Carbohydrates by the Use of Olefin Metathesis
作者:Anders E. Håkansson、Anders Palmelund、Henriette Holm、Robert Madsen
DOI:10.1002/chem.200501429
日期:2006.4.12
stereocontrolled synthesis of (+)-7-deoxypancratistatin is described. The convergent synthesis has been achieved by two different strategies, both of which commence from a pentose and piperonal. The latter is converted into allylic bromide 7, which is then coupled with a protected methyl 5-deoxy-5-iodo-D-ribofuranoside in the presence of zinc metal. The first strategy involves a total of only 13 steps from D-ribose
描述了(+)-7-脱氧胰抑素的立体控制合成。通过两种不同的策略实现了收敛的合成,这两种策略均从戊糖和胡椒醛开始。后者被转化为烯丙基溴化物7,然后在锌金属存在下将其与保护的甲基5-脱氧-5-碘-D-核呋喃呋喃糖苷偶联。第一种策略仅涉及D-核糖和胡椒醛的13个步骤,但在核糖呋喃糖苷9,苄胺和溴化物7之间的锌介导反应中收率低。第二种策略涉及D的总计18个步骤。 -木糖和胡椒醛。前者被转化为呋喃核糖核苷28,后者在锌的存在下与溴化物7偶联,然后进行闭环烯烃复分解反应。随后的Overman重排,二羟基化,