Highly diastereoselective approach to novel phenylindolizidinols via benzothieno analogues of tylophorine based on reductive desulfurization of benzo[b]thiophene
作者:Peter Šafář、Jozefína Žúžiová、Štefan Marchalín、Eva Tóthová、Nadežda Prónayová、Ľubomír Švorc、Viktor Vrábel、Adam Daïch
DOI:10.1016/j.tetasy.2009.02.042
日期:2009.3
Chiral tetra- and hexahydro[1]benzothieno[2,3-f]indolizines 3-5, 9, and 11 were synthesized easily from benzo[b]thiophene-2-carboxaldehyde (1) and (S)-glutamic acid (2) in good overall yields and both high enantio- and diastereomeric purities. Applying a diastereoselective reductive desulfurization of benzo[b]thiophene followed by lactam reduction, epimeric alcohols 4a and 4b were readily converted into (7R or S,8aS)-phenylindolizidinols 6a,c. During these studies, the reduction of benzothienoindolizines 3-5, 9, 11, and 12, was investigated and the results obtained are also discussed. (C) 2009 Elsevier Ltd. All rights reserved.