R. Sercheli et al., TRANSITION-METAL-CATALYZED AUTOXIDATION OF CIS-PINANE AND TRANS-PINANE TO A MIXTURE OF DIASTEREOISOMERIC PINANOLS, Journal of agricultural and food chemistry, 45(4), 1997, pp. 1361-1364
Autoxidations of the pinanes, obtained after hydrogenation of naturall
y occurring Pinus elliottii oil, were performed with or Without solven
t, using the catalytic system Co(OAc)(2)/Mn(OAc)(2)/NH4Br in a 9:1:5 m
olar ratio, and dioxygen as the oxidant. The best selectivity for the
pinanols was 71% (cis:trans ratio, 3:1) with 17% conversion. Autoxidat
ions were also carried out in the absence of catalyst. The hydroperoxi
des formed with 17% conversion were decomposed with Na2SO3 and PPh3, r
esulting in 62% pinanols (cis:trans ratio, 5:1). The pyrolysis of the
pinanols at 600 degrees C and a contact time of 1.15 x 10(-2) s/mol yi
elded 54% of linalool. The side products were mainly due to an ''ene''
reaction, giving diastereoisomeric 1,2-dimethyl-3-isopropenylcyclopen
tanols.