Cyclic acetals derived from pinacol and formaldehyde and acetaldehyde react
with acetonitrile to give 2,4,4,5,5-pentamethyl-4,5-dihydrooxazole no such
reaction occurs with analogous cyclic acetals derived from ethylene glycol
and 1,2-propanediol. These data are consistent with the results of compute
r simulation of the reaction mechanism in terms of SCF MO LCAO approximatio
n (AM1 parametrization).