Grubbs Hexane

To a solution of Grubbs catalyst G1 (943 mg, 1.15 mmol, 0.4 equiv) in CH2C12 (900 mL) was added a solution of enyne 51 (2.00 g, 2.86 mmol, 1.0 equiv) in toluene (100mL). The reaction was purged with ethylene and stirred at 45 °C under an atmosphere of ethylene for 40 h. The crude mixture was treated with ethyl vinyl ether (1 mL) and concentrated to a black oil. Purification by silica gel chromatography (doped with triethylamine, 5-6% in CH2Cl2/hexane) afforded cyclophane 53 (624 mg, 31%). 

To a solution of diolefinic compound (10) (0.6 g, 1.98 mmol) in dry dichloromethane (400ml) at room temperature Grubbs catalyst (0.163 g, 10 mol %) was added. The reaction mixture was stirred for 6 hours under nitrogen atmosphere at the same temperature. Reaction was monitered by TLC (30% ethyl acetate in hexane). After completion of reaction, solvent was removed under reduced pressure using rotary evaporator. Then purified by silica gel (60-120 mesh) column chromatography using ehyl acetate hexane (1 4) to give pure product (11) (0.45... 

The cis- and rraw5-pent-2-enes were purchased by Fluka and distilled prior to use. They were kept over molecular sieves. -hexane and chlorobenzene, purchased by Aldrich, were distilled over Na/K and P2O5 respectively prior to use. The Grubbs and Schrock carbenes were obtained from Strem and used without purification. The Basset carbene was synthesized according to the literature [7]. 

To a solution of olefin 336a (77.0 mg, 0.377 mmol) in CH2CI2 (5.0 mL, 0.075 M) were added Grubbs 11 (32.0 mg, 0.038 mmol) and styrene (0.086 mL, 0.754 mmol) under N2 atmosphere. After refluxing for 8 h, the mixture was allowed to warm to room temperature and concentrated in vacuo. The residue was purified by column chromatography (silica gel, hexanes/EtOAc, 3/1) to afford the desired tetrahydropyran 3.57 (72.3 mg, 68 %) as a colorless oil whose spectral data were in accordance with synthetic 337 reported previously [38] NMR... 

Octavinylsilsesquioxane, 9-(4-vinylphenyl)anthracene, dry dich-loromethane, n-hexane, first generation Grubbs catalyst, silica gel 60, 9-(4-vinylphenyl)anthracene was prepared according to the literature procedure (14). 

---