Photoinduced molecular transformations. Part 113. One-step transformations of cyclic ethers into ω-iodoalkyl formates and of aldehyde cyclic acetals into monoesters of α,ω-alkanediols by iodoxyl radical

Abstract

The reaction of cyclic ethers with iodoxyl radical iodine oxide [generated by irradiation of iodine oxide formed in situ with red mercury(II) oxide and iodine] gives the corresponding ω-iodoalkyl formates in one step; tetrahydrofuran can be transformed into ω-iodoalkyl formate in 31% yield. Aldehyde cyclic acetals under conditions similar to the reaction of cyclic ethers lead to monoesters of α,ω-alkanediols in one step; cyclohexanecarboxaldehyde ethylene acetal gives 2-hydroxy cyclohexanecarboxylate in 60% yield. The pathways leading to ω-iodoalkyl formates and monoesters of α,ω-alkanediols are discussed based on the results of ¹⁸O-labelling studies with ¹⁸·OI and I₂¹⁸O.