Intramolecular cyclization of 3,4-epoxy-alcohols; oxetan formation

1-(βγ-Epoxypropyl)cyclohexan-1-ol (1) and its methyl analogues (2) and (3), when treated with base in 75% aqueous Me2SO, gave the corresponding oxetans (4)–(6) as the main products, while treatment of (1) under anhydrous conditions afforded the oxolan dimer (11) as the sole identified product.