Process for the preparation of bicyclic compounds and the use of this process for the preparation of an ice inhibitor compound

A subject of the present invention is a novel process for the preparation of bicyclic compounds and the use of this process as an intermediate stage in the preparation of a compound which inhibits the interleukin-1 beta converting enzyme (ICE). A method for preparing compounds of formula (I) wherein R is selected from the group consisting of H. alkyl, aryl, and aralkyl of up to 18 carbon atoms and the amine function may be free or protected from a compound of formula (IA) wherein cyclization is carried out in a basic medium and in the presence of a phosphonic acid derivative and the use of said method as an intermediate step for preparing a compound inhibiting the interleukin-1 beta conversion enzyme.