A tetrapeptide type-B CCK receptor ligand of the formula
A-B-C-D
or a pharmaceutically acceptable salt thereof, which is useful for treating central nervous system disorders, substance abuse, gastrointestinal disorders, endocrine disorders, eating-related disorders and treatment of shock, respiratory and cardiocirculatory insufficiencies.
Abstract A rapid entry into naturally occurring and biologically important 1-oxygenated carbazole clausine E was established through Wittigreaction and annulation. Further O-prenylation of clausine E by Mitsunobu reaction followed by p-Claisen rearrangement delivered clausine F. A rapid entry into naturally occurring and biologically important 1-oxygenated carbazole clausine E was established through