A new route to (-)-agelastatin A is reported. The requisite nitrogen functionalities of the agelastatin core have been installed by intramolecular aziridination of an azidoformate and subsequent regioselective azidation, leading to net trans-diamination of the double bond. The present synthesis also demonstrates two new protocols for the preparation of an imidazolidinone hemiaminal motif from an oxazolidinone intermediate which comprise sequential N-tert-butoxycarbonylation, urea formation, hydrolysis, and oxidative cyclization, and direct aminolysis and subsequent oxidative cyclization.

The second-generation approach to (-)-agelastatin A has been established. The present strategy features the FeBr(2)-mediated radical cyclization of 2-cyclopentenyloxycarbonyl azide that allows for the stereoselective installation of a cis-vicinal aminobromo functionality suitable for producing the BCD-ring system of agelastatin A. The aminobromination method streamlines access to oxazolidinone, a key intermediate in the previously reported synthesis, thereby culminating in the new total synthesis of (-)-agelastatin A.

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Other bioactive products U 1300 Synthesis of Chaetomellic Anhydride A, a Potent Inhibitor of RAS Protein Farnesyltransferase. -A short and high-yielding route to chaetomellic anhydride A (IV) is elaborated using the palladium-catalyzed carboxylation of triflate (II) with sodium formate as key step. -(YOSHIMITSU*, T.; ARANO, Y.; KAJI, T.; INO, T.; NAGAOKA, H.; TANAKA, T.; Heterocycles 77 (2009) 1, 179-186; Grad. Sch. Pharm. Sci., Osaka Univ., Suita, Osaka 565, Japan; Eng.) -R. Staver 22-207