Convenient preparation of O-linked polymer-bound N-substituted hydroxylamines, intermediates for synthesis of N-substituted hydroxamic acids

An efficient procedure for preparation of O-linked polymer-bound N-substitu ted hydroxylamines by reduction of resin-bound oximes with borane pyridine complex in the presence of dichloroacetic acid is reported. Other reducing systems commonly used for imine or oxime reduction were ineffective, includ ing borane pyridine in the presence of acetic acid. Grimes derived from a v ariety of aromatic and aliphatic aldehydes and ketones were successfully re duced. The N-substituted products were acylated and cleaved from resin to a fford N-substituted hydroxamic acids.