Chiral Catalyst-Directed Dynamic Kinetic Diastereoselective Acylation of Lactols for <i>De Novo</i> Synthesis of Carbohydrate
作者:Hao-Yuan Wang、Ka Yang、Dan Yin、Can Liu、Daniel A. Glazier、Weiping Tang
DOI:10.1021/acs.orglett.5b02641
日期:2015.11.6
major challenges of synthetic carbohydrate chemistry. We have developed a new strategy consisting of a chiral catalyst-directed acylation followed by a palladium-catalyzed glycosidation to achieve high α- and β-stereoselectivity on the anomeric position. The former process involves a dynamickinetic diastereoselective acylation of lactols derived fromAchmatowiczrearrangement, while the latter is a stereospecific
Expeditious Metal-Free Access to Functionalized Polycyclic Acetals under Mild Aqueous Conditions
作者:Sanghratna Kasare、Siddheshwar K. Bankar、S. S. V. Ramasastry
DOI:10.1021/ol501986f
日期:2014.8.15
A facile approach for the synthesis of furopyrans and bicyclic bisacetals under mild aqueous conditions is described. This potentially green, diversity oriented approach involves cascade Michael addition and cycloacetalization of pyranones and 1,3-dicarbonyls. An interesting switch in the product class was observed depending on the type of pyranone employed. Products of type I and II obtained herein are an integral part of several bioactive natural products and medicinally interesting compounds.