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

The electrophilic cleavage of a cyclopropane single bond in tetracyclo[3.2.0.0 2,7 .0 4,6 ]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 [2.2.1.0 2,6 ]-heptane, C 14 H 15 NO 3 S. This species crystallizes in space group P2 1 /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 13 C nmr spectroscopy made in this laboratory and indicate the danger of basing assignments of configuration in nortricyclenes entirely upon this technique.