Synthesis of new functionalized organoselenium compounds by heterocyclization of selenium dihalides with pent-4-en-1-ol

The reaction of selenium dihalides with pent-4-en-1-ol has been carried out for the first time. Efficient procedures for the synthesis of previously unknown bis(tetrahydrofuran-2-ylmethyl) selenide, dihalobis( tetrahydrofuran-2-ylmethyl)-λ⁴-selanes, and bis(tetrahydrofuran-2-ylmethyl) selenoxide have been developed on the basis of this reaction. The product structures have been studied by ¹H, ¹³C, and ⁷⁷Se NMR. Bis(tetrahydrofuran-2-ylmethyl) selenide and dihalobis(tetrahydrofuran-2-ylmethyl)-λ⁴-selanes represent equimolar mixtures of two diastereoisomers which display different signals in the ¹³C and ⁷⁷Se NMR spectra. The oxidation of bis(tetrahydrofuran-2-ylmethyl) selenide with sodium periodate in methanol leads to the corresponding selenoxide consisting of 4 diastereoisomers.