- Source: Casiraghi formylation
In organic synthesis, the Casiraghi formylation is the formation of a salicylaldehyde from a phenol and paraformaldehyde. The reaction requires a strong Brønsted base and a weak Lewis acid, and gives a methanol coproduct:
(H2CO)2n + nB + nLA + nHArOH → nHC(=O)ArOH + n[HB][LA:OMe]
Formally, it combines the Cannizzaro disproportionation with a directed Friedel-Crafts acylation.
In Casiraghi's original 1978 formulation, Grignard reagents served as both the hindered base and Lewis acid.
Applications include the synthesis of tocopherol derivatives.
