RuO4-catalysed oxidative cyclisation of 1,6-dienes to trans-2,6-bis(hydroxymethyl)tetrahydropyranyldiols. A novel stereoselective process

RuO4 catalyses the stereoselective oxidative cyclisation of the 1,6-dienes, 7-methyl-1,6-octadiene and 1,6-heptadiene, to the corresponding trans-2,6-bis(hydroxymethyl)tetrahydropyranyldiols, in the presence of NaIO4 as primary oxidant, in EtOAc:CH3CN:H2O (3:3:1) at 0°C for 4 min. A mechanistic hypothesis explaining the observed trans-2,6-stereochemical control is formulated.