| Abstract: | Lead tetraacetate (LTA) oxidation of the allylic alcohols 1, 10, 14 and 19 leads to the formation of the epoxides 2, 11, 15 and 20 , products of a novel internal addition reaction of the electron deficient alcohol oxygen to the allylic double bond. In some cases ( 10, 14 ) the formation of a new type of acetoxylated enolethers ( 12, 16 ) is observed. The LTA oxidation of the allylic dienols 21 and 29 gives rise to the formation of the epoxyacetates 25 and 33 , products of a similar internal addition reaction. Furthermore, a variety of cyclization products ( 22, 23, 24, 26, 30, 31, 32 and 34 ) has been isolated whose formation requires an isomerisation of the allylic trans double bond to a cis one. |
