(tert-Butyldimethylsilyl)allene (CAS no.: ), which is also known as Silane, (1,1-dimethylethyl)dimethyl-1,2-propadienyl-, could be produced through the following synthetic routes.

A. 2-oxytetrahydropyran . An oven-dried, 2-L, three-necked, round-bottomed flask is equipped with a large football-shaped -coated magnetic stirring bar, a rubber septum, an argon inlet adapter, and an oven-dried, 200-mL, pressure-equalizing addition funnel sealed with a rubber septum. The flask is charged sequentially with 0.116 g (0.500 mmol) of (±)-camphorsulfonic acid, 750 mL of dichloromethane, and 29.4 mL (0.500 mol) of propargyl alcohol under an argon atmosphere. The flask is cooled to 0°C in an ice-water bath, and a solution of 50.2 mL (0.550 mol) of 3,4-dihydro-2H-pyran in 75 mL of dichloromethane is added dropwise to the reaction mixture over 2 hr. Upon completion of the addition, the ice-water bath is removed, and the reaction mixture is allowed to warm to 23°C. After 2 hr at 23°C, the reaction mixture is transferred to a 2-L separatory funnel and extracted with 100 mL of saturated sodium bicarbonate solution. The organic phase is separated and washed with 100 mL of saturated sodium chloride solution, dried over anhydrous sodium sulfate , filtered, and concentrated under reduced pressure. The residue is purified by distillation through a 15-cm Vigreux column at reduced pressure (13 mm) to afford 67.0 g (96%) of 2-propargyloxytetrahydropyran as a colorless liquid.

B. 3-(tert-Butyldimethylsilyl)-2-propyn-1-ol. An oven-dried, 250-mL, three-necked, round-bottomed flask equipped with a Teflon-coated magnetic stirring bar is sealed under argon with three rubber septa, one of which contains a needle adapter to an argon-filled balloon. The flask is charged with 19.5 g (139 mmol) of 2-propargyloxytetrahydropyran and 140 mL of tetrahydrofuran (THF) and cooled to -78°C in a dry ice-acetone bath. To the well-stirred solution, 13.9 mL (139 mmol) of a 10.0 M solution of butyllithium in hexanes is added slowly via syringe over 15 min. The resulting yellow solution is stirred for 5 min at -78°C, after which time the dry ice-acetone bath is removed and replaced with an ice-water bath, and the reaction mixture is stirred for 15 min at 0°C. One of the septa is removed, 22.0 g (146 mmol) of solid tert-butyldimethylsilyl chloride is added to the reaction mixture in one portion, and the reaction flask is sealed again with a rubber septum. After an additional 2 min at 0°C, the ice-water bath is removed. Within 15 min an exotherm is observed (up to 40°C), followed by a slow return to room temperature. The orange-red reaction mixture is poured into a 1-L separatory funnel containing 250 mL of aqueous 10% sodium chloride solution and 250 mL of hexanes . The layers are mixed vigorously and separated. The aqueous layer is extracted with two 125-mL portions of hexanes , and the combined organic extracts are dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue is transferred to a 1-L round-bottomed flask equipped with a Teflon-coated magnetic stirring bar. To this flask, 500 mL of anhydrous methanol is added, followed by 0.530 g (2.79 mmol) of p-toluenesulfonic acid monohydrate. The flask is sealed with a rubber septum containing a needle adapter to an argon-filled balloon. The reaction mixture is stirred at 23°C for 2 hr and then quenched by the addition of 100 mL of an aqueous saturated sodium bicarbonate solution. The resulting suspension is stirred for an additional 10 min, after which time the mixture is concentrated under reduced pressure to remove most of the methanol. The residue is transferred to a 1-L separatory funnel containing 250 mL of an aqueous 10% sodium chloride solution, and the mixture is extracted with three 200-mL portions of 1:1 hexanes-ethyl acetate . The combined organic extracts are dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue is purified by distillation at reduced pressure (1.5 mm) using a 15-cm Vigreux column to afford 22.0 g (93%) of 3-(tert-butyldimethylsilyl)-2-propyn-1-ol as a colorless oil that solidifies on standing at 23 °C.

C. (tert-Butyldimethylsilyl)allene . An oven-dried, 500-mL, round-bottomed flask equipped with a large football-shaped Teflon-coated magnetic stirring bar is charged with 15.7 g (60.0 mmol) of triphenylphosphine under an argon atmosphere. The flask is sealed with a rubber septum containing a needle adapter to an argon-filled balloon, and 120 mL of THF is added via cannula. The solution is cooled in a -15°C bath, and 9.02 mL (57.5 mmol) of diethyl azodicarboxylate is added via syringe over 2 min, followed immediately by the addition of a solution of 8.52 g (50.0 mmol) of 3-(tert-butyldimethylsilyl)-2-propyn-1-ol in 18 mL of THF via cannula over 2 min. After an additional 5 min, a solution of 13.0 g (60.0 mmol) of o-nitrobenzenesulfonyl hydrazide in 65 mL of THF is added to the reaction mixture over 5 min via cannula. The resulting orange-red solution is stirred at -15°C for 45 min, after which time the cold mixture is allowed to warm to 23°C and is held at that temperature for 5 hr. During this time, the evolution of dinitrogen is observed. The reaction mixture is poured into a 2-L separatory funnel containing 400 mL of pentane , and the resulting mixture is washed with four 500-mL portions of ice-cold water. The organic layer is dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation at 0°C. The residue is purified by flash chromatography using a short column of 230-400 mesh silica gel (60 g, packed dry and eluted with pentane). The fractions containing the product are concentrated by rotary evaporation at 0°C to afford 5.38-5.39 g (70%) of (tert-butyldimethylsilyl)allene as a colorless liquid.