REGIOSELECTIVE RING-OPENING REACTION OF 2-MONO-SUBSTITUTED AZETIDIN-3-ONES PROMOTED BY THE COMBINED USE OF TITANIUM TETRAIODIDE AND ITS CHLORO OR BROMO COUNTERPART

摘要

The ring-opening reaction of 2-mono-substituted azetidin-3-ones at the more substituted bond occurred with the combined use of TiI4 and TiCl4 to give the corresponding ketones in moderate to high yields with high regioselectivity. The reductive aldol reaction of the enolate thus prepared proceeded with chloral in the presence of Pd(O2CCF3)2 to give the syn-aldol adduct in moderate yield.