Gassman-Amick reaction

Common syntheses of aromatic aldehydes employ a) the Gatter-mann reaction, b) the Vilsmeier-Haack reaction, c) formylation with dichlorodimethyl ether (DCDME), d) the Dulf reaction, and e) the Gassman-Amick reaction (see Scheme 14). Aromatic aldehydes can be protected either as diacetates or SchifTs base. 

Gassman and Amick introduced two methods, both similar to 2,4-rearrangement to effect ortho formylation of phenols. Although products were obtained in only moderate (20-45%) yields, the reactions are attractive in effecting exclusive ortho substitution (Eq... 

Aryloxysulphonium Ylides.—Aryloxysulphonium ylides are known to undergo [2,3]-sigmatropic (Sommelet) rearrangements. Gassman and Amick have exploited this reaction for the orMo-functionalization of phenols, as illustrated by their synthesis of (26). 

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