Refunctionalization of Homoallylic Alcohols Containing a Vinylic Chlorine Atom

The chlorine atoms in Z‐substituted vinyl chlorides 1, 5, 7 and 14 have been replaced by alkyl, vinyl and (trimethylsilyl)methyl groups to give the alkenes 3, 4, the dienes 9, 10, 15, or the allylsilanes 8. The latter have been transformed stereoselectively into tri‐ and tetrasubstituted tetrahydrofurans 18 and 20. The vinyl chlorides 1 have been converted into the corresponding Z‐vinylsilanes 13 and 23. These serve as starting compounds for the stereoselective generation of trisubstituted 5,6‐dihydro‐2H‐pyrans 25, 26, 28, and 30. Derivatives 31 and 34 of the vinyl chlorides 1 have been subjected to stereoselective free‐radical cyclizations giving substituted tetrahydropyrans 33 and 35. The vinyl chlorides 1 may readily be converted to the alkynes 37.