Oleanolic acid derivative 1 is an oleanolic acid derivative, which is a novel triterpenoid-steroid hybrid molecule.
Oleanolic acid suppress transcription or translation of inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2) genes. extracted from the reference, compound 9a. In the strategy, it was ambiguous whether phosphorus pentachloride (PCl5) would give the desired ring contraction product 9a in the first step according to classical procedures[1].
[1]. Tadashi Honda, et al. Design and Synthesis of 23,24-Dinoroleanolic Acid Derivatives, Novel Triterpenoid-Steroid Hybrid Molecules. J. Org. Chem., 1998, 63 (14), pp 4846-4849.