Synthesis and crystal structure of (Z)-1-(phenylsulphenyl)-2-phenylethenyl p-toluenesulfonate

The reaction between 1-phenylsulphenyl-2-phenylethyne and p-toluenesulfonic acid in methylene chloride gives (Z)-1-(phenylsulphenyl)-2-phenylethenyl p-toluenesulfonate (1) in good yields. This reaction is both a regio- and a stereospecific cis addition, confirmed by X-ray crystal structure analysis of the title compound. 1 crystallizes in the monoclinic space group P21/n with the lattice parameters a = 10.556(3), b = 9.730(3), c = 19.687(3) Å, β = 105.05(2)°, V = 1952.7(8) Å3, and Z = 4. The results of elemental analysis, IR and NMR spectroscopy are included.