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The total synthesis of iromycin, a microbial metabolite conducted by using a flexible and highly convergent approach demonstrated its interesting biological activity as a NO synthase inhibitor.

The synthesis of functionalized 2-alkyl-idenepyrrolidines and pyrroles by the reaction of 1,3-bis-silyl enol ethers with 2-azido-1,1-dimethoxyethane and subsequent Staudinger-aza-Witting reaction is reported. The condensation of 1,3-dicarbonyl dianions with [alpha]-azidoketones afforded open-chained condensation products that were transformed into pyrroles by dreactions and the subsequent treatment with trifluoroacetic acid.

Treatment of γ-azido-β-hydroxyketones with triphenylphosphine resulted, depending on the structural features of the starting materials, in a domino "Staudinger/semi-aza-Wittig/fragmentation" reaction rather than a normal aza-Wittig reaction. 2-Azido-1-hydroxy-1-(2,4-dioxoalkyl)cyclopentanes, readily available by condensation of 1,3-dicarbonyl dianions with 2-azidocyclopentanone, proved to be optimal starting materials for these reactions which afforded 1-(1,3-dioxoalkyl)amino-2-(alkylidene)cyclopentanes. [ABSTRACT FROM AUTHOR]