Preparation of (2-naphthyl)methylene acetals of glycosides and their hydrogenolytic transformation into 2-naphthylmethyl (NAP) ethers

被引：35

作者：

Lipták, A

Borbás, A

Jánossy, L

Szilágyi, L

机构：

[1] Hungarian Acad Sci, Res Grp Carbohydrates, H-4010 Debrecen, Hungary

[2] Univ Debrecen, Dept Biochem, H-4010 Debrecen, Hungary

[3] Univ Debrecen, Dept Organ Chem, H-4010 Debrecen, Hungary

来源：

TETRAHEDRON LETTERS | 2000年 / 41卷 / 25期

基金：

匈牙利科学研究基金会;

关键词：

D O I：

10.1016/S0040-4039(00)00735-8

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Dioxane- and dioxolane-type (2-naphthyl)methylene acetals of glycosides were prepared by acid-catalyzed transacetalization reactions. The acetals were cleaved using either AlH3 (LiAlH4:AlCl3=3:1), NaCNBH3-HCl or BH3 . Me3N-AlCl3 reagents. Reaction of the 4,6-O-acetals with AlH3 yielded 4-ONAP ethers whereas the other two reagents gave 6-ONAP derivatives with excellent regioselectivity. In dioxolane-type acetals the direction of the cleavage with all three reagents is determined by the stereochemistry of the acetal center; equatorial ONAP/axial-hydroxy derivatives are obtained from the exo-naphthyl isomers; endo-naphthyl acetals, on the other hand, give rise to the formation of axial ONAP/equatorial-hydroxy compounds. The NAP ether and the (2-naphthyl)methylene acetal protecting groups can both be readily removed by treatment with DDQ. (C) 2000 Elsevier Science Ltd. All rights reserved.

引用

页码：4949 / 4953

页数：5

共 20 条

[1] Use of the benzyl radical in syntheses of methylated sugars Part I 4 6-dimethyl glucose [J].