ChemInform Abstract: OXIDATION OF 3‐CARENE BY THALLIUM(III) ACETATE

Monoterpenoids

“…351 The same reagent oxidizes car-2-ene (327) to a mixture of (324), (325), and (328)-- (331).352 Oxidation of car-2-ene (327) by potassium permanganate yields the keto-acid (332a), whose ethyl ester reacts with PC15 and POC13 to give (332b). Elimination of HC1 from (332b) and hydrolysis of the product gives the cyclopropanecarboxylic acid (333), which exhibits insecticidal a~t i v i t y .~s~ The isomeric epoxide (338) yields (339) and (340), together with some of the car-3(10)-ene derivative (341), under the same conditions.…”

“…The reaction proceeds via the (347), and toluene-psulphonic acid in refluxing benzene converts (346) into carvenone and the isomeric ketone (348). 357 Photolysis of the acetyl derivative (349) gives a mixture of (350) and (351). If the irradiation is through a Corex filter, and (349) is in solution in acetone, the products are the cyclopentenes (352) and (353).…”

“…The autoxidation of ( +)-car-3-ene (1 26) in aprotic solvents yields 3-methylacetophenone (321) as the major With T~(OAC)~, car-3-ene is oxidized to a mixture of ( 322)-( 325), together with a diol which may be (326). 351 The same reagent oxidizes car-2-ene (327) to a mixture of (324), (325), and (328)-- (331).352 Oxidation of car-2-ene (327) by potassium permanganate yields the keto-acid (332a), whose ethyl ester reacts with PC15 and POC13 to give (332b). Elimination of HC1 from (332b) and hydrolysis of the product gives the cyclopropanecarboxylic acid (333), which exhibits insecticidal a ~t i v i t y .…”

“…ref. 351). Cold, concentrated sulphuric acid causes the a-epoxide (334) to isomerize to carvenone (345) in high yield.…”

“…The reaction proceeds via the ketone (346). 357 Treatment of (346) with trifluoroacetic acid gives carvenone together with the ester (347), and toluene-psulphonic acid in refluxing benzene converts (346) into carvenone and the isomeric ketone (348).357 Photolysis of the acetyl derivative (349) gives a mixture of (350) and (351). If the irradiation is through a Corex filter, and (349) is in solution in acetone, the products are the cyclopentenes (352) and (353).358 Photolysis of the methoxy-ketone (354), in ethanol solution, gives the cleavage product (359, while its epimer (356) yields ( 357) and (358), which are the known irradiation products of cis-caran-4-one (359).…”