A thirteen step route to the tricyclic ketopyrrole core of roseophilin is presented in which the final step consists of a Paal–Knorr pyrrole synthesis that proceeds with in situ oxidation.
Preparation of the tricyclic ketopyrrole core of roseophilin by radical macrocyclisation and Paal–Knorr condensation
作者:Jeremy Robertson、Richard J. D. Hatley、David J. Watkin
DOI:10.1039/b005351l
日期:——
A concise synthesis of the tricyclic ketopyrrole segment of roseophilin is described in which key features include stereoselective conjugate addition to monosubstituted cyclopentenones, optimised conditions for the rearrangement of 1°-propargylic alcohols to vinyl ketones, 13-endo-trig free-radical macrocyclisation, and PaalâKnorr pyrrole condensation accompanied by oxidation in situ to complete the synthesis. Model studies on methylene oxidation α- to pyrrole rings are also described.