Abstract 1-Mesityl allene (1), 1-mesityl-3-methyl allene (2) and 1-mesityl-3, 3-dimethyl allene (3) rearrange thermally at 150–190 in decane via [1, 5s] sigmatropic H-shifts to yield the o- quinodimethanes 4, which cyclise to give the 1, 2-dihydronaphthalenes 5 and 6 and/or undergo [1, 7 a] sigmatropic H-shifts to give 1-mesityl-(Z)-buta-1, 3-dienes (Z)-7 and (Z)-8, respectively (Schemes 1, 3, 4 and 5) in almost quantitative yields. The activation ...
