Weinreb and Jeong. Org. Let., 2006, ASAP. DOI: 10.1021/ol060556c
Using some really smart 1,3-di-polar chemistry, Weinreb has completed a formal synthesis of Haouamine. Working towards the Baran indenotetrahydropyridine pentacyclic intermediate, they used a 1,3-DPC to put in the indene system very quickly, but isolated two products from the cyclisation. However, the undesired product was converted to the desired by simply heating, resulting in a 76% yield.
However, the ambitious RCM chemistry using a terminal vinyl chloride was less successful, and required a rethink to complete this work.