Asymmetric 1,3-dipolar reactions of 3-sulfinylfuran-2(5 H )-ones with 11 H -dibenzo[ b,e ]azepine 5-oxide. Synthesis of pyrroloazepines via isoxazoloazepines
作者:José L. Garcı́a Ruano、J. Ignacio Andrés Gil、Alberto Fraile、Ana Marı́a Martı́n Castro、M. Rosario Martı́n
DOI:10.1016/j.tetlet.2004.04.108
日期:2004.6
The addition of morphanthridine N-oxide (1) to homochiral 3-p-tolylsulfinylfuran-2(5H)-ones (2a and 2b) under mild conditions affords furoisoxazoloazepines (3a and 3b) in high yields and with complete regioselectivity. The pi-facial and endo-selectivities are also complete from 2a, which yields anti-3a-endo as the only diastereoisomer, whereas cycloreversion determines that the anti-3b-endo adduct can be almost exclusively isolated from 2b. Proper manipulation of the furoisoxazoloazepines allows the synthesis of the optically pure isoxazoloazepines and pyrroloazepines. (C) 2004 Elsevier Ltd. All rights reserved.