Synthesis of Naturally Occurring (Z)-3-Benzylidenephthalide and (.+-.) 3-Benzylphthalides.

A convenient method, involving the generation of the phthalide anion, is described for the synthesis of naturally occurring (Z)-3-benzylidenephthalide (5) and (±) 3-benzylphthalides (6c, 10a–c), starting from phthalides (7a and 7b).