1: 99 percent / pyridine / 3.5 h / Ambient temperature 2: 73 percent / dichloromaleic anhydride / 200 °C 3: 99 percent / 2 M KOH / ethanol / 19 h / Heating 4: 72 percent / CBr4, PPh3 / CH2Cl2 / 6 h / Ambient temperature 5: n-BuLi / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 3.5 h, 2.) -78 deg C to r.t., 17 h 6: p-TsOH*H2O / methanol / 1 h / Heating 7: 68 percent / CBr4, PPh3 / diethyl ether; CH2Cl2 / 1.) 0 deg C, 1 h, 2.) r.t., 17 h 8: 1.) EtMgBr, 2.) CuCN / 1.) THF, reflux, 1 h; r.t., 15 min, 2.) 0 deg C, 1 h; r.t., 2.75 h 9: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 10: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

1: 73 percent / dichloromaleic anhydride / 200 °C 2: 99 percent / 2 M KOH / ethanol / 19 h / Heating 3: 72 percent / CBr4, PPh3 / CH2Cl2 / 6 h / Ambient temperature 4: n-BuLi / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 3.5 h, 2.) -78 deg C to r.t., 17 h 5: p-TsOH*H2O / methanol / 1 h / Heating 6: 68 percent / CBr4, PPh3 / diethyl ether; CH2Cl2 / 1.) 0 deg C, 1 h, 2.) r.t., 17 h 7: 1.) EtMgBr, 2.) CuCN / 1.) THF, reflux, 1 h; r.t., 15 min, 2.) 0 deg C, 1 h; r.t., 2.75 h 8: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 9: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

1: n-BuLi / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 3.5 h, 2.) -78 deg C to r.t., 17 h 2: p-TsOH*H2O / methanol / 1 h / Heating 3: 68 percent / CBr4, PPh3 / diethyl ether; CH2Cl2 / 1.) 0 deg C, 1 h, 2.) r.t., 17 h 4: 1.) EtMgBr, 2.) CuCN / 1.) THF, reflux, 1 h; r.t., 15 min, 2.) 0 deg C, 1 h; r.t., 2.75 h 5: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 6: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

1: 72 percent / CBr4, PPh3 / CH2Cl2 / 6 h / Ambient temperature 2: n-BuLi / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 3.5 h, 2.) -78 deg C to r.t., 17 h 3: p-TsOH*H2O / methanol / 1 h / Heating 4: 68 percent / CBr4, PPh3 / diethyl ether; CH2Cl2 / 1.) 0 deg C, 1 h, 2.) r.t., 17 h 5: 1.) EtMgBr, 2.) CuCN / 1.) THF, reflux, 1 h; r.t., 15 min, 2.) 0 deg C, 1 h; r.t., 2.75 h 6: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 7: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

1: 1.) EtMgBr, 2.) CuCN / 1.) THF, reflux, 1 h; r.t., 15 min, 2.) 0 deg C, 1 h; r.t., 2.75 h 2: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 3: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

1: 68 percent / CBr4, PPh3 / diethyl ether; CH2Cl2 / 1.) 0 deg C, 1 h, 2.) r.t., 17 h 2: 1.) EtMgBr, 2.) CuCN / 1.) THF, reflux, 1 h; r.t., 15 min, 2.) 0 deg C, 1 h; r.t., 2.75 h 3: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 4: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

1: 99 percent / 2 M KOH / ethanol / 19 h / Heating 2: 72 percent / CBr4, PPh3 / CH2Cl2 / 6 h / Ambient temperature 3: n-BuLi / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 3.5 h, 2.) -78 deg C to r.t., 17 h 4: p-TsOH*H2O / methanol / 1 h / Heating 5: 68 percent / CBr4, PPh3 / diethyl ether; CH2Cl2 / 1.) 0 deg C, 1 h, 2.) r.t., 17 h 6: 1.) EtMgBr, 2.) CuCN / 1.) THF, reflux, 1 h; r.t., 15 min, 2.) 0 deg C, 1 h; r.t., 2.75 h 7: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 8: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

1: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 2: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

1: p-TsOH*H2O / methanol / 1 h / Heating 2: 68 percent / CBr4, PPh3 / diethyl ether; CH2Cl2 / 1.) 0 deg C, 1 h, 2.) r.t., 17 h 3: 1.) EtMgBr, 2.) CuCN / 1.) THF, reflux, 1 h; r.t., 15 min, 2.) 0 deg C, 1 h; r.t., 2.75 h 4: H2, quinoline / 5percent Pd/BaSO4 / pyridine / Ambient temperature 5: 69 percent / AlI3, (+)-limonene / CS2 / 1.) r.t., 10 min, 2.) reflux, 30 min View Scheme

t-BuSLi in N,N-dimethyl-formamide