Synthetic Studies of Microcolin B.

Abstract The octanoyl and desacetyl analogue of the lipopeptide microcolin B isolated from Lyngbya majuscula was synthesized using a segment condensation strategy. To achieve this the unique 1-prolyl-methyl-2-pyrroline unit was prepared from Boc-Pro-Ala-OH in a five step synthesis. This segment was coupled to the dipeptide Boc-Thr-MeVal-OH using PyBoP®. Deprotection followed by PyBroP®-mediated coupling with octanoyl-MeLeu-OH finally led to the octanoyl analogue of desacetylmicrocolin B.