(-)-α-Pinene could be produced through the following synthetic routes.

A. 3-aminopropylamide (KAPA). To a bottle of 22.4% potassium hydride in oil is added a -covered magnetic stirring bar. The contents are agitated by first shaking and then stirring until a visually uniform dispersion is attained. Then 17.8 g (0.10 mol) of the dispersion is transferred to an oven-dried 250-mL flask, fitted with a magnetic stirring bar, a septum-capped inlet, and an adapter connected to a pressure-relief bubbler (mercury or oil). The apparatus is purged with dry argon or nitrogen. The flask is charged with 100 mL of dry pentane or other volatile hydrocarbon solvent, and the contents are stirred thoroughly. The stirrer is stopped to allow the potassium hydride to settle, assisted by gentle tapping on the flask, and the supernatant liquid is drawn off with a double-ended needle under inert-gas pressure. This procedure is repeated twice to complete removal of the oil. Residual solvent is then removed in a stream of dry gas. To the dry potassium hydride powder is added rapidly 100 mL of dry 3-aminopropylamine. Caution! gas evolution. Hydrogen evolution commences immediately and subsides after 1.5–2 hr. Formation of KAPA is complete at this time.

B. (-)-α-Pinene. Concurrently, a 3-L, three-necked, round-bottomed flask (fitted with a septum-capped adapter, gastight mechanical stirrer, and a tube adapter connected to a gas bubbler) is purged with inert gas. The flask is then charged with 1588 mL of (-)-β-pinene. To the vigorously stirred pinene at 25°C is added the KAPA (0.1 mol) prepared in part A, using a double-ended needle, over 15 min. The reaction mixture is stirred for 24 hr at 25°C and is then quenched by addition of 100 mL of ice-cold water. The reaction mixture is transferred to a separatory funnel, washed with two 100-mL portions of water, and dried with anhydrous calcium chloride. The crude pinene is decanted from the calcium chloride through a plug of glass wool and distilled at reduced pressure from lithium aluminium hydride. The yield of (-)-α-pinene, bp 72–73°C (46 mm), [α]D23 -47.45° (neat, 92% ee), is 1264 g (93%). The chemical and isomeric purity is 99% by GLC.

Notice: Potassium hydride is highly reactive toward water. Material separated from protective oil or solvent should not be exposed to air, but should be kept under argon or nitrogen.