Singlet oxygen photolysis of dihaloketones: a novel approach to vicinal triketones and their monohydrates

ABSTRACT

Vicinal triketones 1 and their monohydrates 2 have received remarkable interest by virtue of their wide applications for analytical and synthetic purposes. Thus, they are used for the-analysis of amino-acids [Strecker-degradation] in a quantitative manner as well as for the detection of peptides, proteins, primary amines and ammonia, particularly, in biological fluids. The methods that described for preparation of triones 1 are, however, indirect and lengthy. Moreover, no common procedure links these methods in one approach which can be generalized for producing these polycarbonyl compounds This along with our growing interest devoted to the chemistry of vicinal triketones and their monohydrates, have prompted us to develop a new simple approach for the production of triones 1 and/or their hydrated form 2. This depends upon the photosensitized oxidation of gemdihaloketones 4 to give the beseeched compounds, directly, and in a high percentage yield