Reactivity of vinyl sulphonic esters. Part XIV. Addition of trinitrobenzenesulphonyl hypohalites to acetylene derivatives to give β-halogenovinyl sulphonates
The synthesis of several β-halogenovinyl 2,4,6-trinitrobenzenesulphonates, R2(Hal)C:C(O3STnp)R1(Hal = Cl, Br, or I) by addition of trinitrobenzenesulphonyl hypohalites to substituted diphenylacetylenes or alkynes is reported. The stereochemistry and orientation of the addition are discussed in terms of the structure of the vinyl cation intermediate, which may be either bridged or open depending on the nature of the halogens and of the residues R2 and R1 linked to the unsaturated system.