Modular synthesis of oxazolines and their derivatives.

A class of modular oxazolines and their derivatives 1-5 were synthesized with moderate to excellent yields using a simple one-pot method; 4 x 3 bis-oxazolines were obtained, as expected, from each of the three reactions of 1,4-dicyanobenzene, 1,3-dicyanobenzene, and 1,2-dicyanobenzene with optically active amino alcohols in chlorobenzene under dry, anaerobic conditions. ZnCl(2) was used as a Lewis acid catalyst. Direct condensation of 1, 2-bis(cyanomethyl) benzene or 2-cyanophenylacetonitrile did not yield the target products, but two series of novel compounds (4 and 5) were isolated and their structures were confirmed by X-Ray analysis. All products (1-5) were characterized by NMR, IR, and MS.