A STUDY OF THE GAS-PHASE INTERCONVERSION OF 1-(2-ARYLOXYPHENYL)ALKANIMINYL AND 2-(ARYLIMINOMETHYL)PHENOXYL RADICALS

Flash vacuum pyrolysis of the allyl ethers 9-11 and of the oxime ether s 15-17 at 650 degrees C (5 x 10(-2)-5 x 10(-3) Torr) generates 2-(ary liminomethyl)phenoxyl radicals 4 and 1-(2-aryloxyphenyl)alkaniminyl ra dicals 5 respectively which can interconvert via a spirodienyl radical leading to common products which are generally isolated in low to mod erate yield, The iminyls 5 normally undergo beta-cleavage leading to n itriles (e.g. 21) and/or to benzofurans (e.g. 22) after cyclisation, T he phenoxyls 4 show more complex behaviour dominated by hydrogen abstr action processes leading to products such as phenols (e.g. 32), the in dole 27 or phenanthridines 34 and 35.