Two-step one-pot Johnson-Claisen rearrangement/hydroformylation of renewable feedstocks

The chemical modification of naturally occurring compounds, e.g., terpenes, opens a path to new products potentially useful for the flavor & fragrance industry. Hydroformylation allows the introduction of the olfactorily relevant formyl group in a C-C double-bound, but its direct application to these substrates often is not straightforward because of the steric hinderance of the olefin moieties. In this work, we developed an efficient two-step one-pot protocol involving a Johnson-Claisen rearrangement followed by hydroformylation, which allowed transforming natural products containing an allyl alcohol moiety (linalool, nerol, cinnamyl alcohol, myrtenol, perillyl alcohol, and carveol) into derivatives containing an aldehyde and an ester functional group, both related to desirable olfactive properties in fragrances.