Ethanone, 1-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphthalenyl)- → HCID 19002101, compound

Participants

Reaction Steps

In a nitrogen-filled glove box, to 250 ml round bottomed flask fitted with a magnetic stirring bar containing 1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-yl)ethanone (0.5 g, 2.05 mmol) and 50 ml of dry THF was added [+PPh3MeI−] (1.24 g, 3.07 mmol), followed by tBuOK (343 g, 3.06 mmol). The mixture was stirred at room temperature. After 24 h, in situ GC/MS analysis showed complete conversion of the carbonyl compound to the alkene product. The mixture was filtered to remove the salt. The solvent was removed in vacuo and the resulting solid was redissolved in hexane and then cooled in the refrigerator for 24 h to crystallise the PPh3O. The mixture was filtered and cooled again to remove additional PPh3O. This step has to be repeated at least 4 times to remove all of the PPh3O. Finally, the solvent was removed in vacuo to obtain the pure alkene. Alternatively, a faster method of purification, after removal of the salt by filtration, involves concentration in vacuo and then Kugelrohr distillation (100-140° C., 3×10−4 torr), which gave an analytically pure sample of 4a (396 mg, 80%); m.p. 39-40° C.

Provenance & Evidence