A simple method for the α-oxygenation of aldehydes

A mild, efficient and general method for the chemospecific α-oxygenation of aldehydes is described. Treatment of a series of aldehydes with N-tert-butyl-O-benzoyl hydroxylamine hydrochloride gives the corresponding α-oxygenated carbonyl via a proposed pericyclic rearrangement process

A general method for the α-acyloxylation of carbonyl compounds

A simple, one-pot method for the α-acyloxylation of carbonyl compds. that proceeded at room temp. in the presence of both moisture and air has been developed. Treatment of a variety of aldehydes and both cyclic and acyclic ketones with N-methyl-O-benzoylhydroxylamine hydrochloride provided the α-functionalized product in good isolated yield. The transformation was tolerant of a wide range of functional groups and, significantly, was regiospecific in the discrimination of secondary over primary centers in the case of nonsym. substrates

Polypyrroles as antioxidants: Kinetic studies on reactions of bilirubin and biliverdin dimethyl esters and synthetic model compounds with peroxyl radicals in solution. Chemical calculations on selected typical structures

Rate constants for hydrogen-atom transfer (HAT) from bilirubin dimethyl ester (BRDE) and biliverdin dimethyl ester (BVDE) to peroxyl radicals during inhibited autoxidation of styrene initiated by azobisisobutyronitrile (AIBN) were kinh(BRDE) = 22.5 ×4 and kinh(BVDE) = 10.2 × 104 M-1 s-1, and the stoichiometric factors (n) were 2.0 and 2.7, respectively. A synthetic tetrapyrrole (bis(dipyrromethene)) containing the α-central (2,2′) CH2 linkage gave kin