Unexpected ring-expansion of 1,2-benzisoxazol-3-ones

A novel and unexpected ring-expansion reaction of 1,2-benzisoxazol-3-ones is identified. The scope of this reaction is exemplified and the proposed mechanism is also implicated in another degradation process. This reaction also represents a new method for accessing the 4H-1,3-benzoxazin-4-one skeleton.

An unexpected ring-expansion reaction of 1,2-benzisoxazol-3-ones is identified. The scope of this reaction is exemplified and the proposed mechanism is also implicated in another degradation process. This reaction also represents a new method for accessing the 4H-1,3-benzoxazin-4-one skeleton.