Glucal

About: Glucal is a research topic. Over the lifetime, 590 publications have been published within this topic receiving 8960 citations. The topic is also known as: D-glucal.

Syntheses of l-glucosamine donors for 1,2-trans-glycosylation reactions

Abstract: Two new l -glucosamine donors, that is pent-4-enyl 3,4,6-tri- O -acetyl-2-allyloxycarbonylamino-2-deoxy-β- l -glucopyranoside 16 and ethyl 3,4,6-tri- O -acetyl-2-allyloxycarbonylamino-2-deoxy-1-thio-β- l -glucopyranoside 21 were prepared in 12 steps from l -arabinose. The reaction pathway uses 3,4,6-tri- O -acetyl- l -glucal 5 , and then 3,4,6-tri- O -acetyl-2-deoxy-2-iodo-α- l -mannopyranosyl azide 8 as intermediates. The latter, together with donors 16 and 21 , were used for preparing l -glucosamine neoglycolipids.

HClO4 x SiO2 catalysed synthesis of alkyl 3-deoxy-hex-2-enopyranosides from 2-hydroxy glucal ester: application in the synthesis of a cis-fused bicyclic ether and a 4-amino-C-glucoside.

Abstract: A variety of alcohols react with 2,3,4,6-tetra-O-acetyl-1,5-anhydro-D-arabino-hex-1-enopyranose 1 in the presence of a catalytic amount of HClO(4) supported on silica gel to give the corresponding alkyl 3-deoxy-hex-2-enopyranosides 2 in high yield, with short reaction times (10-45 mins) and good alpha-selectivity. Work-up merely involves filtration of the reagent, followed by chromatographic purification of the crude product. This methodology has also been employed in the synthesis of a bicyclic ether, a useful precursor for cyclic polyethers, and a 4-amino-C-glucoside.