Regio- and chemoselective reductive cleavage of 4,6-O-benzylidene-type acetals of hexopyranosides using BH3·THF–TMSOTf
作者:Katalin Daragics、Péter Fügedi
DOI:10.1016/j.tetlet.2009.03.194
日期:2009.6
cyclic acetals of carbohydrates undergo efficient reductive ring opening using BH3·THF and a catalytic amount of TMSOTf at room temperature. 4,6-O-Benzylidene-hexopyranosides afford the corresponding 4-O-benzyl ethers exclusively, in high yields. Other benzylidene-type acetals, such as naphthylmethylene and 4-methoxybenzylidene acetals are also cleaved with the same reagent. The conversions are highly regio-
碳水化合物的亚苄基型环状缩醛在室温下使用BH 3 ·THF和催化量的TMSOTf进行有效的还原性开环。4,6- ø -亚苄基- hexopyranosides得到相应的4- ø -苄基醚排他地,以高收率。其他亚苄基型缩醛,例如萘基亚甲基和4-甲氧基亚苄基缩醛也可以用相同的试剂裂解。该转化具有高度的区域选择性和立体选择性,并以优异的产率提供了苄基型醚。