The total synthesis of (±)-aspergilline A (1) is described. Key features of the synthesis include pyrrolinone formation via reaction of an intermediate propargyl amine with a methyl malonyl chloride derived ammonium enolate and a formal [3+2] cycloaddition between an imidate and cyclopropenone.

A method for chemoselective carbonyl ylide formation utilizing the Rh(II) catalyzed decomposition of electronically differentiated diazo malonates is disclosed. Treatment of ethyl, trifluoro ethyl diazo malonate with a Rh(II) catalyst selectively forms a carbonyl ylide from the relatively electron rich ethyl ester. This carbonyl ylide can be trapped by various alkynes giving highly functionalized oxabicyclic compounds in a chemo-, regio-, and diastereoselective fashion.

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Chemoselective Intramolecular Carbonyl Ylide Formation Through Electronically Differentiated Malonate Diesters. -Trapping of the carbonyl ylides by alkynes is examined, and depending on the ylides substituents either functionalized oxabicyclic compounds are produced in a chemo-, regio-and diastereoselective manner or tetronic acids are obtained as mixtures of diastereomers. -(NAKHLA, M. C.; LEE, C.-W.; WOOD*, J. L.; Org. Lett. 17 (2015) 23, 5760-5763, http://dx.