The total synthesis of clemochinenoside A and the first total syntheses of clemochinenoside B and berchemolide were achieved simultaneously via macrocyclization of 4-O-(4-O-(F13)benzyl-beta-D-glucopyranosyl)syringic acid with 4-O-(4-O-(F17)-benzyl-beta-D-glucopyranosyl)vanillic acid by a fluorous mixture synthetic method. The spectroscopic data of the synthetic products were identical with those of the natural products, although the optical rotation of clemochinenoside A differed from the published values in sign and magnitude. (C) 2009 Elsevier Ltd. All rights reserved.
A practical fluorous benzylidene acetal protecting group for a quick synthesis of disaccharides
作者:Masaru Kojima、Yutaka Nakamura、Seiji Takeuchi
DOI:10.1016/j.tetlet.2007.04.106
日期:2007.6
A new fluorous benzylidene acetalprotectinggroup was regioselectively introduced into carbohydrates, deprotected under acidic conditions, and reused. Oligosaccharides were synthesized via regioselective conversion of the fluorous acetalgroup to the benzyl group by traditional reaction conditions. The fluorous compounds were easily separated from non-fluorous by-products by fluorous solid phase extraction