29868-42-6Relevant articles and documents
Highly Regioselective Monoacylation of Unprotected Glucopyranoside Using Transient Directing-Protecting Groups
Rocheleau, Sylvain,Pottel, Joshua,Huski?, Igor,Moitessier, Nicolas
, p. 646 - 656 (2017/02/05)
The regioselective functionalization of monosaccharides is notoriously achieved using metal catalysis, lengthy synthetic strategies requiring protection/deprotection, various enzymes, or other methods that target cis-diols (and thus cannot be used with glucopyranose derivatives), In this paper, we report a new method using selected boronic acids as temporary protecting groups, and describe its application to the regioselective functionalization of methyl α-d-glucopyranoside, the most difficult monosaccharide to functionalize regioselectively. Generally, reactions of glucopyranosides may lead to a plethora of mono- and polyfunctionalized derivatives, yet our method gave the 3-O-acetylated, 2-O-benzoylated, and 2-O-pivaloylated derivatives of methyl α-d-glucopyranoside as major products. We focused on the use of recyclable and green temporary protecting groups (in a one-pot reaction) and on the modulation of the intramolecular hydrogen-bonding network using selected arylboronic acids. A complete scalable procedure leading to a single regioisomer from unprotected methyl α-d-glucopyranoside is presented.
Facile chelation-controlled reductive opening of methoxybenzylidene acetals with Bu3SnH and MgBr2. Regioselective protection strategy as MPM ethers
Zheng,Yamauchi,Dei,Kusaka,Matsui,Yonemitsu
, p. 6441 - 6445 (2007/10/03)
A mild and efficient regioselective reductive opening of methoxybenzylidene acetals using a combination of Bu3SnH and MgBr2·OEt2, mainly via five-membered chelation intermediates is described. This reaction was applied to synthetic intermediates of myriaporon and tedanolide. (C) 2000 Elsevier Science Ltd.