A new general method for the synthesis of polyenes involving 1,6-, 1,8-, 1,10- and 1,12-carbonyl group transpositions via #alpha#-oxoketene dithioacetals

摘要

A novel strategy for hitherto unreorted even numbered i.e 1,6 -, 1,8-, 1,10- and 1,12-carbonyl transpositions has been demonstrated on newly synthesized model cyclopropyl polyenones 2a-h by subjecting them to either 1,2- reduction or 1,2- alkylative addition followed by solvolysis in the presence of BF_3.Et_2O/HgCl_2/MeOH o give novel polyene esters 4a-h, 10h and 10g in highly regio- and stereoselective manner.