(E)-1-Phenyl-3,3-dimethyl-1-butene (CAS NO.: ), with other names as , (3,3-dimethyl-1-butenyl)- (E)-, could be produced through the following synthetic routes.

A. (E)-2-Methyl-2-(2-phenylethenyl)-1,3-dithiolane (CAS NO.: ). In a 500-mL, round-bottomed flask equipped with a magnetic stirring bar are placed 29.2 g (0.2 mol) of (E)-4-phenyl-3-buten-2-one and 20.7 g (0.22 mol) of 1,2-ethanedithiol in 200 mL of methanol. To the stirred solution is added 11 mL (12.4 g, 0.087 mol) of boron trifluoride etherate. The mixture is stirred at room temperature for 45 min. To the mixture is added 50 mL of aqueous 10% sodium hydroxide, and the methanol is removed under reduced pressure. (300 mL) is introduced and the solution is washed with aqueous 10% sodium hydroxide solution (2 × 100 mL). The aqueous layer is extracted with dichloromethane (3 × 200 mL). The combined organic layers are washed with 200 mL of water, dried over anhydrous magnesium sulfate, and filtered. The solvent is removed under reduced pressure and the residue is fractionally distilled to give 24.9–27.1 g (56–61%) of (E)-2-methyl-2-(2-phenylethenyl)-1,3-dithiolane as a yellowish liquid, bp 109–112°C (0.16 mm), that solidifies on standing, mp 52–53°C.

B. Methylmagnesium iodide (CAS NO.: ). A 500-mL, three-necked, round-bottomed flask containing 9.7 g (0.4 g-atom) of magnesium turnings is equipped with a rubber septum, reflux condenser, an addition funnel, and a magnetic stirring bar. The system is flame-dried and flushed with nitrogen. Anhydrous ether (20 mL) is introduced to cover the magnesium. As the contents of the flask are stirred, iodomethane (56.7 g, 0.4 mol) in 180 mL of anhydrous ether is added dropwise through the addition funnel. The addition requires about 2 hr; the mixture is then stirred for an additional 30 min.

C. (E)-1-Phenyl-3,3-dimethyl-1-butene (CAS NO.: ). In a 1-L, two-necked, round-bottomed flask fitted with a reflux condenser, rubber septum, and a magnetic stirring bar are placed 17.8 g (0.08 mol) of 2-methyl-2-(2-phenylethenyl)-1,3-dithiolane and 2.17 g (0.004 mol) of [1,3-bis(diphenylphosphino)propane]nickel(II) chloride [NiCl₂(dppp)]. The flask is evacuated and flushed with nitrogen three times. To the above mixture is added 300 mL of anhydrous tetrahydrofuran. The ether solution of methylmagnesium iodide prepared in Step B is introduced with a double-ended needle in one portion. The mixture is heated under reflux for 24 hr, cooled to room temperature, and treated with 200 mL of saturated ammonium chloride solution. The organic layer is separated and the aqueous layer is extracted with ether (3 × 200-mL). The combined organic layers are washed twice with aqueous 10% sodium hydroxide solution (100 mL) and with brine (100 mL). The organic solution is dried over anhydrous magnesium sulfate. The solvent is removed under reduced pressure and the residue is filtered through a short column packed with 30 g of silica gel and flushed under a positive nitrogen pressure with 350 mL of hexane. After the solvent is evaporated under reduced pressure, the yellowish residue is distilled through a spinning band to give 10.4 g (81%) of (E)-1-phenyl-3,3-dimethyl-1-butene as a colorless liquid, bp 91–93°C/30 mm.