Preparation of six membered carbocycles by aryl-tellurium mediated free-radical cyclisation

Abstract Radical cyclisation of various telluro-compounds was examined. Olefins conjugated to an electron withdrawing group, ( 7, 8, 9, 10, and 11 ) gave high yields of the corresponding six membered products. Non-activated olefin 23 gave the corresponding thiopyridyl derivative 24 as the only product. The photolysis, using oxime 18 as radicophile for the cylisation, proceeded slowly at room temperature, and gave only a low yield of products 19 and 20 .