Biomimetic Total Synthesis of Enterocin
Lilla Koser, Vivian Miles Lechner, Thorsten Bach
Abstract
The first chemical total synthesis of the highly oxygenated polyketide enterocin has been accomplished. The key step of the synthesis was a late-stage biomimetic reaction cascade involving two intramolecular aldol reactions in which each step proceeded in 52 % yield (averaged) and which established four of the seven stereogenic centers. The pivotal precursor for the cascade reaction was assembled from three readily available building blocks. A chiral dithioacetal with two stereogenic centers originating from L-arabinose represented the core fragment to both ends of which the other building blocks were attached by aldol reactions. The remaining stereogenic center was installed by Davis oxygenation immediately prior to the key step.