Sweet smell of success for perfume production
14 Nov 2002
Chemists at Valencia Polytechnic University in Spain have discovered a way to catalyse reactions which are important to perfume manufacturers.
Avelino Corma and colleagues at the University's Chemical Technology Institute have found a heterogeneous catalyst for the synthesis of cyclic acetals, organic compounds which have flowery scents. Currently, acetals are made using strong acids as homogeneous catalysts, which makes it difficult to separate and purify the products.
Corma's team has found that the conversion of methyl naphthyl ketone and propylene glycol into 2-methyl-2-napthyl-4-methyl-1,3-dioxolane - which smells of orange blossom - can be catalysed using solid acids, rather than the usual catalyst, p-toluenesulfonic acid. The best catalysts are tridirectional zeolites, and the activity can be increased greatly if small crystallites of the catalyst are used, they add.
Separation is simple, they add, and the product does not contain acid residues, making it suitable for use in a perfume to be applied to skin.
The same technique can also be applied to other scents, they say. Cyclic acetal compounds smelling of green apple, hyacinth, violet and vanilla can all be made using the same approach, says Corma, and the system is both cheaper and technically superior to the homogeneous system.
Corma's team has published its results in the journal Green Chemistry.
