Stereochemistry of seven-membered heterocycles 5. The conformation of 1.3-dioxacyclohept-5-enes

1. According, to the results of dipole moment and IR and Raman spectroscopy methods, the butenediol acetal's (I)-(IX) are characterized by a conformational equilibrium of the chair and twist forms determined by the influence of various factors. 2. In the determination of the conformational equilibrium of the 2-alkyl-substituted acetals the influence of the "alkyl" dipole must be taken into account. © 1981 Plenum Publishing Corporation