Microwave-Assisted Synthesis of Chiral Oxime Ethers

Abstract

An efficient and rapid synthesis of a new class of chiral oxime ethers has been achieved via two-step reaction in which the first step is the reaction of oximes 1a-f with ethyl bromoacetate in the presence of sodium hydride to give oxime ethers 2a-f which are subsequently, in the second step, reacted with different commercially available chiral amines under microwave irradiation conditions to give compounds 3a-l in good to excellent yields. Through this method, we have observed a decrease in reaction time and excellent yields than the previously described conventional method.

Polytopal Rearrangement Governing Stereochemistry of Bicyclic Oxime Ether Synthesis

“…Microwave-assisted synthesis has a large impact on synthetic organic chemistry. Microwave-enhanced organic synthesis typically reduces reaction times and sometimes improves product yields [ 14 ]. In order to determine the influence of reaction conditions on the product isomer ratio, several microwave-assisted reactions were conducted ( Table 3 ).…”

“…The aim was to investigate the stereoselectivity of reactions and the influence of the reaction conditions on ( E ) and ( Z ) ratios. For this purpose, three different methods were used and compared: solvent [ 10 ], mechanochemical [ 12 , 13 ] and microwave [ 14 , 15 ] synthesis. Recent studies reported mechanochemical and microwave syntheses of oxime heterocyclic compounds and defined the stereoselectivity of those reactions [ 16 , 17 , 18 ].…”