METHYL INSERTION REACTIONS OF TETRAHYDROPYRANS HAVING A C1'-MESYLOXY GROUP ON THE C2-SIDE CHAIN WITH TRIMETHYLALUMINUM

摘要

Methyl insertion reactions of tetrahydropyrans having a C1'-mesyloxy group on the C2-side chain, mediated by trimethylaluminum, were investigated. Removal of the mesyloxy group, 1,2-hydride shift and/or ring-expansion, and methyl insertion took place conceitedly, depending on the stereostructure of the substrate, to give 2-methylated tetrahydropyran and/or 2- or 3-methylated oxepane.