Electrophilic cleavage of cyclopropanes. IV. The reaction of 2-nitrobenzenesulphenyl chloride with tetracyclo[3.2.0.02,7.04,6]heptane in methanol and acetic acid: the crystal structure of exo-3-(2′-nitrophenylthio)-exo-5-methoxytricyclo[2.2.1.02,6]heptane, C14H15NO3S

Abstract

The electrophilic cleavage of a cyclopropane single bond in tetracyclo[3.2.0.02,7.04,6]heptane by 2-nitrobenzenesulphenyl chloride in methanol and acetic acid has been studied using both nmr and single crystal X-ray structural determination techniques. The orientation of ring opening has been shown to be inversion as a result of electrophilic corner attack. The crystal structure of one adduct allowed the unambiguous assignment of exo-3-(2′-nitrophenylthio)-exo-5-methoxytricyclo [2.2.1.02,6]-heptane, C14H15NO3S. This species crystallizes in space group P21/a with unit cell dimensions a = 10.633(1), b = 13.637(1), c = 9.938(1) Å, β = 115.36(1)°, Z = 4. The structure was solved by MULTAN 78. The parameters were refined by block-diagonal least squares to a final R = 0.039 for 2445 observed reflections. Of particular interest is an interaction between the sulphur atom and the oxygen atom of the nitro group with an [Formula: see text] distance of 2.694(2) Å and [Formula: see text]. The data presented in this paper show errors in previous assignments based on 13C nmr spectroscopy made in this laboratory and indicate the danger of basing assignments of configuration in nortricyclenes entirely upon this technique.