Synthesis of Anisomycin

Significance

(-)-Anisomycin is a metabolite of Streptomyces grisoleaus and S. roseochromogenes with fungicidal and in vitro antitumor activity. Synthetic routes to the 3-alkoxy (or hydroxy) pyrrolidine core are of interest as this moiety is found in a number of biologically active natural products. The synthesis of both enantiomers of anisomycin is reported. The most interesting step in this synthesis, the cyclization of the alkoxyallene C to the dihydropyrrole D, is compromised somewhat by the use of a 12-carbon chiral auxiliary to deliver a 3-carbon allene unit with only modest stereoselectivity.