Stereoselective syntheses of chiral (3 S,9b S)-1,2,3,9b-tetrahydro-5 H-imidazo[2,1- a]isoindol-5-ones

Abstract

Chiral (3 S,9b S)-1,2,3,9b-tetrahydro-5 H-imidazo[2,1- a]isoindol-5-ones 11a– 11f, 14b, 14c and 17a, b were prepared in 78–93% yields with high stereoselectivities (d.e. >99%) by the intermolecular condensations of 2-formylbenzoic acids 10 or 13 or 2-acetylbenzoic acid 15 with chiral diamines 9a– 9f and 9h. Compounds 9a– 9f and 9h were readily prepared in three steps from optically active N-Boc-α-amino acids 5a– 5d.