4-tert-Butyl- and 1-(4-tert-Butylcyclohexen-1-yl)-2-propen-1-one could be produced through the following synthetic routes.

A. 4-tert-Butylcyclohexen-1-yl trifluoromethanesulfonate (CAS NO.: ). A dry, 2-L, three-necked, round-bottomed flask equipped with a magnetic stirring bar, an argon inlet, and a condenser is charged with 33.0 g (0.214 mol) of 4-tert-butylcyclohexanone, 1.5 L of dichloromethane, and 49.5 g (0.241 mol) of 2,6-di-tert-butyl-4-methylpyridine. The solution is stirred under a static argon atmosphere and cooled to 0°C, at which time the dropwise addition of 40.0 mL (0.238 mol) of trifluoromethanesulfonic anhydride is begun. After the addition is complete, the brown mixture is allowed to warm slowly to room temperature and is stirred at that temperature for 10 hr. At this point, the consumption of starting ketone is verified by thin-layer chromatography (hexane; silica gel). If the reaction is incomplete, more trifluoromethanesulfonic anhydride is added and additional time is allowed. The solvent is removed by distillation and the resulting light-tan material is treated with 1 L of and heated to reflux for 30 min. The tan salts thus obtained are removed by filtration and washed with five 100-mL portions of pentane. The combined pentane solutions are washed with two 250-mL portions each of a 10% hydrochloric acid solution, a 10% sodium hydroxide solution, and a saturated sodium chloride solution, dried with magnesium sulfate, filtered through a 6 × 4-cm pad of silica gel, and concentrated by distillation. Bulb-to-bulb distillation of the resulting yellow oil at 75–80°C (0.5 mm) gives 43–45 g (70–73%) of the product as a colorless oil.

B. Trimethylvinyltin (CAS NO.: ). To a dry, 1-L, three-necked, round-bottomed flask, equipped with a Dewar-type condenser cooled to -78°C, a magnetic stirring bar and a gas inlet leading to a static supply of dry argon are added 11.4 g (0.469 mol) of clean magnesium turnings, 50 mL of dry tetrahydrofuran, 3 mL of vinyl bromide, and 0.3 mL of methyl iodide to initiate formation of vinylmagnesium bromide. To this is added a solution of 41 mL (0.624 mol or 66.7 g total) of vinyl bromide in 125 mL of dry tetrahydrofuran via cannula at a rate that maintains a gentle reflux. After addition the mixture is heated to reflux for 1 hr with an oil bath and then cooled to 60°C.

To the resulting slurry of vinylmagnesium bromide (with the condenser still maintained at -78°C) is added via cannula a solution of 61.3 g (0.307 mol) of trimethyltin chloride in 50 mL of dry tetrahydrofuran at a rate suitable to maintain a gentle reflux. The temperature is maintained at 60°C for 5 hr and then the mixture is cooled to room temperature. With the condenser still maintained at -78°C, 200 mL of a saturated ammonium chloride solution is added by syringe at a rate that maintains a gentle reflux, followed by 200 mL of water. The resulting solution is transferred to a separatory funnel with the aid of 200 mL of pentane and the organic layer is washed with 250 mL of a saturated ammonium chloride solution. The combined aqueous layers are back-extracted twice with 250 mL of pentane, and the combined organic layers are washed 5 times with 250 mL of saturated ammonium chloride, 10 times with a 10% hydrochloric acid solution, and twice with a saturated sodium chloride solution, and then gravity-filtered through a 9 × 4-cm pad of silica gel to give approximately 500 mL of a slightly yellow solution. Pentanes are removed by distillation using a 16-cm Vigreux column and a short-path stillhead. Continued distillation affords a fraction boiling from 60–90°C, which contains a mixture of 4.9 g of trimethylvinyltin in 16.3 g of tetrahydrofuran. At this point the still is cooled to room temperature, the Vigreux column is removed, and the remaining oil is distilled at 95–100°C to give 38–39 g (64–66% purified yield) of trimethylvinyltin.

C. 4-tert-Butyl-1-vinylcyclohexene (CAS NO.: ). A dry, 2-L, one-necked, round-bottomed flask equipped with a magnetic stirring bar, an argon inlet, and a condenser  is charged with 1.18 g (1.02 mmol) of tetrakis(triphenylphosphine)palladium(0), 12.9 g (0.305 mol) of lithium chloride, and 500 mL of tetrahydrofuran. This mixture is stirred for 15 min under a static argon atmosphere; then a solution of 28.0 g (0.0979 mol) of 4-tert-butylcyclohexen-1-yl trifluoromethanesulfonate and 19.0 g (0.0997 mol) of trimethylvinyltin in 250 mL of tetrahydrofuran is added, followed by an additional 250 mL of tetrahydrofuran. The resulting, almost colorless solution is heated to a gentle reflux for 48 hr. The mixture is cooled to room temperature and partitioned between 500 mL of water and 250 mL of pentane. The aqueous layer is back-extracted with two 200-mL portions of pentane. The combined organic layers are washed with two 250-mL portions each of a concentrated sodium bicarbonate solution, water, and a concentrated sodium chloride solution, dried over magnesium sulfate, filtered through a 4 × 4-cm pad of silica gel and concentrated by distillation using a 10-cm Vigreux column. Bulb-to-bulb distillation of the resulting yellow oil at 65–68°C (0.55 mm) gives 12.6–12.8 g (78–79%) of the coupled product.

D. 1-(4-tert-Butylcyclohexen-1-yl)-2-propen-1-one (CAS NO.: ). To a dry, 2-L, round-bottomed flask, equipped with a magnetic stirring bar, a condenser, and a gas inlet connected to a static argon atmosphere, are added 1.12 g (0.968 mmol) of tetrakis(triphenylphosphine)palladium(0), 13.2 g (0.312 mol) of lithium chloride, and 500 mL of tetrahydrofuran, followed by a solution of 28.6 g (0.100 mol) of 4-tert-butylcyclohexen-1-yl trifluoromethanesulfonate and 19.1 g (0.100 mol) of trimethylvinyltin in 250 mL of tetrahydrofuran, and then an additional 250 mL of tetrahydrofuran. A gas bag filled with carbon monoxide is attached to the gas inlet and the apparatus is flushed with carbon monoxide. The gas bag is refilled with carbon monoxide and reattached to the gas inlet. The mixture is then heated to 55°C. After 2–4 hr, a large amount of the carbon monoxide has been absorbed into solution and the gas bag is refilled and reattached to the gas inlet. After a total of 40 hr, the reaction mixture darkens and is cooled to room temperature. This solution is transferred to a 2-L separatory funnel, diluted with 500 mL of pentane, and washed successively with two 300-mL portions each of water, saturated sodium bicarbonate solution, water again, and saturated sodium chloride solution. The resulting yellow solution is dried over magnesium sulfate, filtered through a 6 × 4-cm pad of silica gel, and concentrated using a rotary evaporator. Slow bulb-to-bulb distillation of the brown oil at 85–95°C (0.35 mm) gives 14.3–14.5 g (74–75%) of the product as a colorless oil.

Notice: Many organotin compounds are toxic.4 Their preparation and use should be carried out in a well-ventilated hood.