| abstract |
Friedel Crafts preparation of aryl carbonyl compounds having an exceptionally high degree of isomeric purity and freedom from by-products can be achieved by adding to the Lewis acid reaction system a protic controlling agent selected from ROX, water, RCOOX, RSO3X, and ROY, wherein R is organic, X is hydrogen or metal, and Y is metal. Contrary to conventional expectation, the protic agent does not significantly alkylate or acylate the Friedel Crafts reaction product. |