Process for producing 2,2,3-trimethylcyclopent-3-enecarbaldehyde (campholytic aldehyde)

A process for the preparation of campholytic aldehyde comprising:

• (a) reacting campholenic aldehyde with an amine of formula (I)
• wherein
• R1 and R2 are independently selected from C1-C6 alkyl or benzyl;
• or
• R1 and R2 forming together with the nitrogen atom to which they are attached a cycling ring containing 4 to 7 carbon atoms and none or one further hetero atom selected from nitrogen and oxygen;
• (b) treating the resulting product of step 1 with oxygen to prepare campholytic aldehyde in the presence of a copper catalyst and a solvent, with the proviso that the solvent is not a chlorinated solvent.