Total synthesis of clavilactone B: a radical cyclization-fragmentation strategy.

A new synthetic route to clavilactone B, a naturally occurring inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, is disclosed. The route features a sequential samarium-mediated radical cyclization-fragmentation of an indanone derivative, which provides rapid access to a 10-membered carbocyclic motif fused to an aromatic ring.

Formal synthesis of (-)-agelastatin A: an iron(II)-mediated cyclization strategy.

An iron(II)-mediated aminohalogenation of a cyclopentenyl N-tosyloxycarbamate provided new access to the key intermediate for the synthesis of (-)-agelastatin A (AA, 1), a potent antiproliferative alkaloid. The present synthetic endeavour offered an insight into the mechanism underlying the iron(II)-mediated aminohalogenation of N-tosyloxycarbamate, in which the radical properties of the N-iron intermediates in the redox states were operative.

Intramolecular iron(II)-catalyzed aminobromination of allyl N-tosyloxycarbamates.

Allyl N-tosyloxycarbamates are found to be catalytically transformed into ß-brominated oxazolidinones with FeBr(2)/n-Bu(4)NBr in t-BuOH.