Total Synthesis of Enisorine D and its Analogues

Abstract

The first total synthesis of enisorine D, a natural product isolated from the marine sponge Iotrochota cf. iota, is described in 64% overall yield. The target molecule, which is an inhibitor of T3SS-dependent Yope secretion of Y. pseudotuberculosis, is achieved in seven linear steps from tyramine via simple and effective transformations that include bromination, acylation, alkylation, azidation, reduction and routine acid–amine coupling. A total of sixteen analogues are prepared by coupling with eight different cinnamic acids, two bromopyrrole carboxylic acids, five phenyl carboxylic acids and picolinic acid.

Evolution of Strategies in Protecting‐Group‐Free Synthesis of Natural Products: A Recent Update

“…[ 122 ] The molaka'iamine core present in them is also found in many similar natural products, all of them exhibit many biological activities such as antifungal, antiviral, antimicrobial and potentially cytotoxic towards cancer cells. [ 123 ] Khan and co‐workers [ 124 ] demonstrated the simple and efficient PGF‐synthesis of enisorine D ( 357 ) (Scheme 42). The tyramine 351 was brominated using literature procedure [ 125 ] to dibromide, which on acylation delivered amide 352 .…”