A Sequential Indium-Mediated Aldehyde Allylation/Palladium-Catalyzed Cross-Coupling Reaction in the Synthesis of 2-Deoxy-β-<i>C</i>-Aryl Glycosides
作者:John Alec Moral、Seong-Jin Moon、Samuel Rodriguez-Torres、Thomas G. Minehan
DOI:10.1021/ol901353f
日期:2009.8.20
Indium-mediated allylation of aldehydes with 2-chloro-3-iodopropene, followed by a palladium-catalyzed cross-coupling reaction with triarylindium reagents or arylboronic acids, leads to aryl-substituted homoallylic alcohols in good to excellent yields and diastereoselectivities. The products obtained from reactions conducted with D-glyceraldehyde acetonide can be transformed into 2-deoxy-beta-C-aryl ribofuranosides in high overall yields. Similarly, 2-deoxy-beta-C-aryl allopyranosides may be prepared efficiently from 2,4-O-benzylidene erythrose.
On the direct 2,3-hydroxyl-group differentiation of tartaric acid esters
作者:James McNulty、Justin Mao
DOI:10.1016/s0040-4039(02)00662-7
日期:2002.5
Direct desymmetrization of tartaricacidesters with TIPS-triflate proceeds in up to 99% yield giving the useful intermediates 2a–b. Selective reduction of the ester groups provides access to fully differentiated threonolactone derivatives while reduction of both esters of 2a followed by periodate mediated diol cleavage allows access to 2-O-TIPS-protected l-glyceraldehyde.
用TIPS-三氟甲磺酸酯对酒石酸酯进行直接脱对称,收率高达99%,提供了有用的中间体2a – b。酯基团的选择性还原提供了完全分化的苏糖内酯衍生物的途径,而2a的两种酯的还原,然后是高碘酸盐介导的二醇裂解,则使得能够获得2 - O -TIPS保护的1-甘油醛。