H°, HH, H1, Hs) (iit.20b.soc,8id,83 nmr spectrum). e«tfo-5-Cyano-exo-5-methyl-( 49) and exo-S-Cyano-endo-S-methylbicydo[2.2.1]hept-2-ene (50). The mixture of isomers from Eastman Kodak Co. was separated by preparative gc (column H, 140°, 60 ml of He/min); retention times exo-cyano 50, 11.6 min; endocyano 49 13.0 min. The following nmr spectral data (CC14) were obtained on the isolated isomers: endo-cyano-49, an apparent triplet centered at -6.28 (2.0 , HA, HB, line separation 1.9 cps), a six-line multiplet centered at -2.95 (1.0 H, Hc or HD, line separations 1.8 cps), a six-line multiplet centered at -2.79 (1.0 H, or Hc, line separations 1.6 cps), a multiplet centered at -1.7(2.2 H, two of the four protons, • • •1), and a singlet at -1.52(CHza) overlapping with a multiplet centered at -1.5 ppm (two remaining protons from /P'.e.h.i) (4.8 H total); exo-cyano-50, an unsymmetrical doublet of doublets centered at -6.25 (1.0 H,
Notes mmol) in dry benzene'(25 ml) at 5 °C was added phosphorus pentachloride (2.08 g, 10 mmol) over a 10-min period. When evolution of hydrogen chloride had ceased, the solution was cooled to 4 °C and a solution of stannic chloride (3.35 g, 13 mmol) in benzene (50 ml) was added dropwise with stirring over a 30-min period. The magenta colored mixture was allowed to warm up to room temperature and was stirred for 2 h. Decomposition of the complex with 0.1 M HC1 and ice, followed by benzene extraction with washing and drying (MgS04), gave, upon removal of the solvent, a yellow oil. This was chromatographed on silica gel using 3:1 benzene-chloroform as eluent to give yellow crystals (1.9 g, 68%) mp 161-162 °C. An analytical sample (mp 162.5-163 °C) was obtained by recrystallization from benzene-hexane as bright yellow prisms with a brilliant green fluorescence: ir (KBr) 1625 cm-1; NMR (Unisol-D) S 7.0-8.3 (m, 8 H, aromatic), 4.6 (s, 2 H,
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