Ozonolytic transformations of (R)-(-)-carvon in the presence of pyridine

Ozonolytic transformations of (R)-(-)-carvone in aprotic (CH2Cl2) and proton-donor (MeOH) solvents in the presence of pyridine were carried out. A low conversion of the starting diene was noted when carrying out controlled ozonolysis by treatment with equivalent of O-3. A mixture of 3-acetyl-5-methoxy-5-oxopentanoic acid and methyl 4-oxo-3-(2-oxoethyl)pentanoate in MeOH and 5-acetyl-2-methylcyclohex-2-en-1-one in CH2Cl2 were formed. Exhaustive ozonolysis of (R)-(-)-carvone in CH2Cl2 in the presence of pyridine leads to 3-acetylpentadioic acid. The monomethyl ether of 3-acetylpentadioic acid and the product of its cyclization-2,8-dioxo-1-methylbicyclo[3.3.0]octane-3,7-dione were formed in MeOH/Py by the treatment of ozone excess.

Automated summary

Ozonolytic transformations of (R)-(-)-carvone were conducted in aprotic and proton-donor solvents in the presence of pyridine, leading to the formation of various compounds, including pentadioic acids and cyclohexenones.