An investigation towards the diastereoselective synthesis of 3-acetoxy/methoxy/phthalimido-β-lactams using chiral imines. Issue 2 (15th February 2017) - Bhalla, Aman
Graphical abstract: Abstract: The efficient diastereoselective synthesis of 3-acetoxy/methoxy/phthalimido-β-lactams2/2′, 3/3′ and4/4′ respectively was performed using chiral imines1 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 –C H (Me/Et)Ph/Np of the two diastereomers. Representative pairs of cis -diastereomers were separated by efficient column chromatography. Abstract : (1′ R, 3 S, 4 R )-1-(1′-Naphthylethyl)-3-acetoxy-4-styrylazetidin-2-one: C25 H23 NO3 [ α ]D 20 = −177 ( c 0.1, chloroform) Source of chirality: ( R )-(+)-1-(1-Naphthyl)ethyl amine Absolute configuration: (1′ R, 3 S, 4 R )