Trisaccharide, esperamicin

Scheme 7-60 Synthesis of the esperamicin A, trisaccharide 288 (Danishefsky and co-workers). (PMB, p-methoxybenzyl TEOC, 2-(trimethylsilyl)ethoxycarbonyl).

Scheme 7-62 The Kahne synthesis of the calicheamicin/esperamicin core trisaccharide fragment 300.

Danishefsky SJ, Halcomb RL (1991) The synthesis of the core trisaccharide of esperamicin corroboration of the proposed structure for its rearrangement product and stabilization of the core trisaccharide domain. J Am Chem Soc 113 5080-5802... 

Synthetic work has been reported on compound 9 which is a hydrolytically stable analogue of GM3 ganglioside lactone. Compound 10, which contains a trisaccharide having a hydrojgrlamine linking unit, and which is a derivative of the carbohydrate domain of calicheamicin, has been reported, and carbohydrate fragments of esperamicin Aj which also contain this type of bonding, have likewise been described. ... 

Cycloaddition of nitrones to 5,6-dideoxy-l,2-0-isopropylidene-a-D-jcy/o-hex-5-enofuranose gave mainly or exclusively the cw-substituted isoxazolines 49. The hydroxylamine-linkage of the esperamicin trisaccharide 51 was constructed by 0-glycosylation of the nitrone 50 followed by deprotection (Scheme 11). ... 

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