Tetrahedron letters

Efficient general asymmetric syntheses of 3-substituted 1 (3H)-isobenzofuranones in very high enantiomeric excess

PV Ramachandran, GM Chen, HC Brown

Index: Ramachandran, P. Veeraraghavan; Chen, Guang-Ming; Brown, Herbert C. Tetrahedron Letters, 1996 , vol. 37, # 13 p. 2205 - 2208

Full Text: HTML

Citation Number: 58

Abstract

The intermolecular asymmetric reduction of methyl o-(1-oxoalkyl) benzoates with B- chlorodiisopinocampheylborane provides, after workup, 3-alkylphthalides in≥ 97% ee. Unfortunately, this procedure is not as efficient for the preparation of 3-arylphthalides. However, an intramolecular reduction of B-(o-benzoylbenzoyloxy) diisopinocampheylborane, readily prepared by the treatment of o-benzoyl benzoic acid ...