A new synthesis of (+)-cyclophellitol, a potent β-glucosidase inhibitor, has been completed in nine steps from d-xylose. The key transformations involve a zinc-mediated fragmentation of benzyl-protected methyl 5-deoxy-5-iodo-xylofuranoside followed by a highly diastereoselective indium-mediated coupling with ethyl 4-bromocrotonate. Subsequent ring-closing olefin metathesis, ester reduction, olefin epoxidation
A convenient approach to the construction of dihydroxylated unsaturated azepanes featuring a functional group (ethoxycarbonyl)methyl or (cyano)methyl at C-2 was achieved from a pent-4-enal synthon obtained in four steps from D-xylose. The key step of the sequence relied on the conjugate addition of allylamine to alpha,beta-unsaturated ester or nitrile, prepared by Wadsworth-Emmons olefination. Subsequent RCM afforded the target unsaturated azepanes. (C) 2012 Elsevier Ltd. All rights reserved.
Synthesis of Cyclophellitol, Cyclophellitol Aziridine, and Their Tagged Derivatives
作者:Kah-Yee Li、Jianbing Jiang、Martin D. Witte、Wouter W. Kallemeijn、Hans van den Elst、Chung-Sing Wong、Sharina D. Chander、Sascha Hoogendoorn、Thomas J. M. Beenakker、Jeroen D. C. Codée、Johannes M. F. G. Aerts、Gijs A. van der Marel、Herman S. Overkleeft
DOI:10.1002/ejoc.201402588
日期:2014.9
epoxides and aziridines are potent and selective irreversible inhibitors of retaining glycosidases. We have previously reported on our studies on the use of activity-based probes derived from cyclophellitol and from its aziridine analogue for activity-based profiling of retaining -glucosidases in vitro, in situ, and in some examples also in vivo. In this work we disclose full details of the synthesis, purification