Hydrogen bonding effects in the epoxidation of propenol with dioxiranes. A DFT computational study

Potential-energy surfaces for the epoxidns. of CH2:CHCH2OH (I) with dioxirane (II) and dimethyldioxirane (III) were studied at the B3LYP/6-31G* level. Seven transition structures (TSs) were located for epoxidn. with II. The four chem. more significant TSs were located also for the reaction with III. Geometries and energies of 2 of them clearly show that stabilizing H-bonding interactions can be at work, and that they involve both dioxirane O atoms. Calcns. indicate that the electron-attracting effect of the allylic hydroxy group has a relatively small rate-retarding effect.