A facile synthetic approach to the core structure of 6,7-didehydrocarnosoic acid type derivatives

In this paper we report on the development of a flexible and efficient synthetic approach towards 6,7-didehydrocarnosoic acid type analogues. The elaboration of the required trans-decalin system, the installation of the carboxylic acid in the angular position as well as the generation of the C6–C7 double bond to afford the 6,7-didehydrocarnosoic acid scaffold as it was found in and is described.