Concise and practical route to tri- and tetra-hydroxy seven-membered iminocyclitols as glycosidase inhibitors from d-(+)-glucurono-γ-lactone
作者:Navnath B. Kalamkar、Vijay M. Kasture、Sanjay T. Chavan、Sushma G. Sabharwal、Dilip D. Dhavale
DOI:10.1016/j.tet.2010.08.060
日期:2010.10
An efficient and short total synthesis of tetrahydroxy-1c and trihydroxy-azepane id is reported in 72% and 57% overall yields, respectively, from D-(+)-glucurono-gamma-lactone. Thus, D-glucuronolactone 2 on acetonide protection. DIBAL-H reduction and one-pot intermolecular reductive amination followed by -NCbz protection afforded 6-(N-benzyl-N-benzyloxycarbonyl) amino-6-deoxy-1,2-O-isopropylidene-alpha-D-gluco-1,4-furanose 5a. 1,2-Acetonide hydrolysis in 5a and Pd-mediated intramolecular reductive aminocyclization afforded tetrahydroxyazepane 1c. An analogous pathway with 5-deoxy-1,2-O-isopropylidene-alpha-D-glucurono-6,3-lactone 3b gave trihydroxy-azepane id. Glycosidase inhibitory activity of 1c/1d was studied and id was found to be potent inhibitor of alpha-mannosidase and beta-galactosidase. (C) 2010 Elsevier Ltd. All rights reserved.