SYNTHESIS OF FRAGRANCES STARTING FROM CYCLIC VINYL KETONES

Synthesis of fragrances, i.e. methyl esters and lactones of cyclic ketones, starts from cyclic vinyl ketones. These react with hydrogen cyanide in the presence of basic catalyst. Formed keto nitriles undergo a reduction of keto group in secondary hydroxy group in the next steps and process is followed by functionalization of cyano group in carboxy or alkoxycarbonyl group. The order of both processes can be exchanged. The final lactonization carry out between hydroxy and (funcionalized) carboxy group under acidic conditions.The functionalization of cyano group and subsequent lactonization take place as a one-pot process. This innovative process is simpler and cheaper and provides products in very good yields and purity, which allows further processing in the synthesis of the final products.