The rearrangement under oxidative conditions of 3-(benzyloxy)-tetrahydro- 2,6,6-trimethyl-2H-pyran-2-carbaldehydes to afford a chiral protected tetrahydrofuran lactol is described.
The influence of different protecting groups in the cyclization of highly substituted α,δ-dihydroxyepoxides has been studied. It is possible to control the opening or the cyclization of the epoxide depending on the protecting group used.