New routes to clavine-type ergot alkaloids. Part 2: Synthesis of the last, so far not yet synthesized member of the clavine alkaloid family, (±)-cycloclavine

Starting from 4-bromo-Uhleʹs ketone (2), an alkylation step using ethyl 3-methylamino-propionate followed by intramolecular aldol condensation in two steps, transformation of the ester group into a methyl group, and finally cyclopropanation of the 8,9 double bond, resulted in a six-step total synthesis of (±)-cycloclavine (1).