An investigation towards the diastereoselective synthesis of 3-acetoxy/methoxy/phthalimido-β-lactams using chiral imines
作者:Aman Bhalla、Garima Modi、S.S. Bari、Anu Kumari、Dipika Narula、Shiwani Berry
DOI:10.1016/j.tetasy.2016.12.007
日期:2017.2
The efficient diastereoselective synthesis of 3-acetoxy/methoxy/phthalimido-beta-lactams 2/2', 3/3' and 4/4' respectively was performed using chiral imines 1 obtained from chiral amines. Factors (solvent, temperature, substituent, steric bulk) influencing the stereoselectivity and the diastereomeric ratio were also studied in detail. The diastereoselectivity of the two isomers was determined from the ratio of integral values of doublets of C3-H and C4-H and from the integral values of H in -CH(Me/Et)Ph/Np of the two diastereomers. Representative pairs of cis-diastereomers were separated by efficient column chromatography. (C) 2016 Elsevier Ltd. All rights reserved.