2-Methyl-5,6-dihydro-2H-pyran in the simmons-smith reaction

2-Methyl-5,6-dihydro-2H-pyran reacts with the Simmons-Smith reagent to give a mixture of 2-ethyl-5,6-dihydro-2H-pyran, cis- and trans-2-methyl-3-oxabicyclo-[4.1.0]heptanes, and 2-methyl-2,5,6,7- or 3-methyl-2,3,6,7-tetrahydrooxepine in a ratio of 2∶2∶5∶1.