Study On Method Of Synthesis Of Helional

Helional is a kind of widely used spice around world, has a gentle floral aroma, dosage is with 20%.because of the flavor is famous preious, the research has important significant in synthesis.The research synthetise helional by heliotropine as raw material step by step, at first piperonylenepropanal is synthesized. The best reaction condition by single factor method is:heliotropine 100g, methanol 100g, propional 40g, potassium hydroxide 3g, reaction temperature 40℃ and time 1.5h, the yield is 71.4%.The second step is piperonylenepropanal hydrogenation helional. The best reaction condition by single factor method is:piperonylenepropanal 100g, methanol 100g,5% Pd/C catalyst 5g, hydrogen pressure 300KPa, reaction temperature 40℃, time 3h, the yield is 93.1%. The total yields 66.5% at two steps. The structure of the two step reaction has been characterized.Then using one-pot synthesis of helional, condensation and hydrogenation are performed in a reaction vessel. The best reaction condition using orthogonal method is: heliotropine 100g, methanol 100g, propional 40g,5% Pd/C catalyst 5g, potassium hydroxide 3g, hydrogen pressure 300KPa, reaction temperature 40℃, time 3h, the yield 64.8%.Compare the two methods, step by step method needs piperonylenepropanal purification and process fussy because of heating to dissolve solid but easy control, however one pot method simplifies the operation and shorten time but affects many factors. It’s a direction for future research of synthetic helional.