Watanabe Toru, Hirai Go, Kato Marie, Hashizume Daisuke, Miyagi Taeko, Sodeoka Mikiko
RIKEN, Hirosawa, Wako 351-0198, Japan.
Org Lett. 2008 Oct 2;10(19):4167-70. doi: 10.1021/ol801519j. Epub 2008 Sep 3.
A CH 2 -linked alpha(2,3)sialylgalactose analogue was efficiently synthesized using an Ireland-Claisen rearrangement, which was developed recently by our group for constructing a CF 2 -sialoside. The reaction conditions of the rearrangement were optimized for alpha-stereoselective formation of the CH 2 -sialoside. On the basis of the observed temperature effects, the origin of the stereoselectivity of the Ireland-Claisen rearrangement is discussed. Moreover, reconstruction of the 2alpha-hydroxyl group on the galactose unit of the rearrangement product was achieved by means of stereoselective dihydroxylation and deoxygenation.
使用我们小组最近开发的用于构建CF₂-唾液酸苷的爱尔兰-克莱森重排反应，高效合成了一种与CH₂相连的α(2,3)唾液酸半乳糖类似物。对重排反应条件进行了优化，以实现CH₂-唾液酸苷的α-立体选择性形成。基于观察到的温度效应，讨论了爱尔兰-克莱森重排反应立体选择性的起源。此外，通过立体选择性双羟基化和脱氧反应，实现了重排产物半乳糖单元上2α-羟基的重建。
