Efficient route to 2H-1,3-oxazines through ring expansion of isoxazoles by rhodium carbenoids
摘要:
Studies related to the total synthesis of elisabethin C led to the discovery of a rhodiurn-catalyzed cascade sequence involving isoxazole ring expansion and a [4+3] cycloaddition. The scope of the isoxazole ring expansion was explored, resulting in the synthesis of a range of 2H-1,3-oxazines in 47-96% yield. (C) 2008 Elsevier Ltd. All rights reserved.