合成和绝对构型分配的环烯醚萜 9-去氧筋骨草苷。

Synthesis and assignment of absolute configuration of the iridoid 9-deoxygelsemide.

机构信息

Dipartimento di Chimica Organica, Università di Pavia, Via Taramelli 10, 27100 Pavia, Italy.

出版信息

Org Lett. 2010 Feb 5;12(3):596-9. doi: 10.1021/ol902809v.

PMID:20038133

Abstract

The first enantioselective synthesis of 9-deoxygelsemide, belonging to a rare group of iridoids isolated from Gelsemium plants, is described. The key synthetic steps are a variant of the Woodward-Prevost reaction to install the characteristic cis-alpha-1,2-dioxygenated system at C-6 and C-7 with complete diastereoselectivity. Construction of the dihydropyran ring was achieved via formylation of lactone I, followed by dehydration of the corresponding lactol. The synthesis allowed assignment of absolute configuration to 9-deoxygelsemide and related iridoids.

摘要

本文描述了属于从钩吻属植物中分离得到的结构罕见的环烯醚萜类化合物的 9-去氧钩吻碱的首次对映选择性全合成。关键的合成步骤是伍德沃德-普雷沃斯特（Woodward-Prevost）反应的变体，以完全非对映选择性在 C-6 和 C-7 位引入特征性的顺式-α-1,2-二氧代系统。通过内酯 I 的甲酰化作用，然后脱水相应的内酯醇，实现了二氢吡喃环的构建。该合成方法允许对 9-去氧钩吻碱和相关的环烯醚萜类化合物进行绝对构型的确定。