Conduramine F-1 epoxides: synthesis and their glycosidase inhibitory activities

Starting from (+/-)-7-oxanorbornenone ((+/-)-14), (+/-)-(1RS, 2RS, 3SR, 6SR)-6-azidocyclohex-4-en-1,2,3-triol ((+/-)-24) and (+/-)- 1RS, 2RS, 3SR, 6RS)-6-azidocyclohex-4-en-1,2,3-triol ((+/-)-26) were obtained. Epoxidation of the latter cyclohexene derivative gave two epoxides (+/-)-30 and (+/-)-31 that were converted into (+/-)-conduramine F-1 epoxides (+/-)-10 and (epoxides (+/-)-30 and (+/-)-31 that were converted into (+/-)-conduramine F-1 epoxides (+/-)-10 and (+/-)-11 and N-substituted derivatives (+/-)-12 and (+/-)-13. Compound (+/-)-(1RS, 2SR, 3RS, 4SR, 5RS, 6SR)-5-({[4-(trifluoromethyl) phenyl] methyl} amino)-7-oxabicyclo[4.1.0]heptane-2,3,4- triol ((+/-)-12c) is a good, non-competitive inhibitor of beta-xylosidase from Aspergillus niger (K-i=2.2 mu M), and (+/-)( 1RS, 2RS, 3SR, 4RS, 5SR, 6SR)-5-{[(biphenyl-4-yl) methyl] amino}-7-oxabicyclo[4.1.0] heptane-2,3,4-triol ((+/-)-13d) is a good inhibitor of alpha-glucosidase from brewer's yeast (Ki 2.8 mu M, non-competitive). (c) 2007 Elsevier Ltd. All rights reserved.