N-Benzyloxymalimide for an easy access to 5-alkyl-3-pyrrolin-2-ones: asymmetric synthesis of the mixed imide substructure of the potent immunosuppressant microcolin B
- 化学化工－已发表论文 
O-Benzyl-N-benzyloxymalimide 12 has been synthesized as a useful variant of the chiral building blocks 9. The advantage of the malimide 12 over 9 was demonstrated by mild and high-yielding reductive N-deprotection of N-benzyloxylactams 18a-i to give a series of (4R,5S)-5-alkyl-4-hydroxy-pyrrolidin-2-ones, which are key intermediates for the asymmetric synthesis of pyrrolidines, pyrrolizidines, and indolizidines, as well as beta-hydroxy gamma-amino acids. Lactam ent-11a has been applied to the synthesis of the mixed imide 25, a key intermediate for the total synthesis of microcolin B, which also demonstrated that lactam ent-11a or 11a can serve as a latent form of the 5-methyl-3-pyrrolin-2-one substructure of majusculamide D 4, deoxymajusculamide D, and the jamaicamides A-C. (C) 2010 Elsevier Ltd. All rights reserved.