Oxiraneethoxytributyltins prepared from the corresponding oxiraneethanols, on heating at∼ 200° gave, after demetalation with isophthallic acid, 2-oxetanemethanols and/or 3- oxolanols. As appears from about thirty rearrangements the choice between oxetane and oxolane formation is dependent on:(1) the relative degree of substitution of the oxirane ring; cyclization occuring predominantly at the more substituted carbon; and (2) the ...