(+-)-alpha-Pinene → Tetraethyl-para-menthane-2,6-diyldiphosphonate

Beteiligte Stoffe

Reaktionsschritte

To a 5-liter vessel equipped with a mechanical stirrer was added 863 ml (6.7 mol) of diethyl hydrogen phosphite (DEHP). The stirred DEHP was heated to 140° and then 12.3 ml (0.067 mol) of di-tertiary-butyl peroxide was added. Finally, α-pinene, 211 ml (1.3 mol), was added dropwise over a period of 10-30 minutes while the reaction temperture was maintained at 140°-150°. This mixture was heated for 5 hours at 140°, cooled at room temperature, and then distilled in vacuo to yield 54.2 g (0.2 mol; 15.4%) of diethyl para-menth-6-en-2-ylphosphonate, bp=180°-185° (1.2 mm), and 376.5 g (0.91 mol, 70.0%) of tetraethyl-para-menthane-2,6-diyldiphosphonate), bp=198° (0.4 mm). The NMR spectrum showed an A2B3 pattern corresponding to the ethyl groups at 4.12δ and 1.35δ along with the remainder of the proton signals between 2.5δ and 0.8δ.

Herkunft & Nachweise