STUDIES ON OXYGEN HETEROCYCLES PART-1 : ACID CATALYSED AND PHOTOCHEMICAL REACTIONS OF SOME ARYLDIAZOKETONES
Trifluoroacetic acid catalysed reaction of 2-methoxyphenyldiazomethylketone (4a), 2-acetoxyphenyldiazomethylketone (4b) and 3-(2-anisyl)-α-diazo-2-propanone (11) leads to the formation of coumaranone (6) and 3-chromanone (12), while 4-(2-anisyl)-α-diazo-2-butanone (16) affords benzo-1-oxepan-3-one (17) and 5-methoxy-2-tetralone (18) in moderate yield.The photochemical decomposition of the said diazoketones (4a, 11 and 16) gave products depending on the length of the side chain present in the substrates.