posted on 2003-04-08, 00:00authored byGerald D. Artman, Steven M. Weinreb
A halogen-selective tandem intramolecular Heck/carbonylation reaction has been developed for the construction of the C,E,F-ring system and
the C20 quaternary center found in perophoramidine (1). This process can be effected in good yields in the presence of both the chlorine and
bromine atoms found in the natural product. In addition, it is possible to introduce the quaternary center at C4 in a stereoselective manner
by a lactone enolate alkylation, using NaH and allyl bromide.