Synthesis of α‐Hydroxy Ketones from Terpene Aldehydes

Abstract

Unsymmetrically substituted α‐hydroxy ketones possessing isoprenoid units within the molecule were synthesised from commercially available terpene aldehydes. The synthesis was applicable to α,β‐unsaturated aldehydes and afforded the respective α‐hydroxy‐methyl ketones in overall good yield. Tautomerisation of these products did not occur under the conditions of reaction but was observed upon heating. Diastereoisomeric α‐hydroxy ketones have been resolved, and X‐ray analysis on one of these analogues allowed for the elucidation of the stereochemistry after conversion into its camphanate ester.

Keywords:

• Acyloins
• α‐Hydroxy ketones
• Terpene aldehydes
• Cyanohydrin trimethylsilyl ethers
• Copper salt catalysis
• Nitriles
• Grignard reaction
• Camphanates
• Tautomerisation