SYNTHETIC APPLICATIONS OF CARBONYL YLIDES GENERATED VIA THE TANDEM CYCLIZATION CYCLOADDITION REACTION OF RHODIUM CARBENOIDS

The author's chemical studies dealing with the generation of carbonyl ylides via the rhodium(II) induced cyclization of alpha-diazo alkanedi ones are summarized. Dipole formation occurs by reaction of a transien t rhodium carbenoid intermediate with a neighboring carbonyl group. Th ese cyclizations are performed under extremely mild conditions, typica lly at room temperature in a neutral organic solvent. Since these cycl oadditions involve carbonyl ylides, the resulting products are oxabicy cles of varying ring size. When the dipolarophile is intramolecularly tethered to the dipole, the subsequent cycloaddition affords complex o xapolycyclic systems with three (or more) component rings.