Synthesis of allyl alcohol as a method to valorise glycerol from the biodiesel production.

Reaction of triglycerides with trimethyl orthoformate in presence of camphorsulfonic acid (CSA) gave the fatty acid methyl esters (FAMEs, 4) in good yield. However, under these conditions, the protected glycerol could not be obtained. Formation of orthoesters 9 was possible in a separate reaction using very weak acidic conditions, namely catalytic amounts of pyridinium para -toluenesulfonate (PPTS). Subjecting the orthoesters 9 to thermolysis at 270 °C gave allyl alcohol (11) with good efficiency.