An unexpected base-promoted isomerization of oxazolinylaryl oxiranes: synthesis of oxazolinylaryl alkanones
摘要:
Aryl substituted oxazolinyloxiranes 1a-g have been found to undergo smooth isomerization into oxazolinyl substituted aryl alkanones 2a-g upon treatment with LDA in Et2O at -98degreesC, warming to room temperature and quenching with satd aq. NH4Cl. A mechanism involving an oxazoline-assisted ortho lithiation of the aryl group (cis to the oxazoline system) of oxiranes 1 is proposed. (C) 2002 Published by Elsevier Science Ltd.