1392848-20-2Relevant academic research and scientific papers
Medium-sized rings versus macrocycles through rhodium-catalyzed ring-expansion reactions of cyclic acetals
Ballesteros-Garrido, Rafael,Rix, Diane,Besnard, Celine,Lacour, Jerome
, p. 6626 - 6631 (2012)
α-Diazo β-ketoesters and diketones react with cyclic acetals under RhII catalysis to yield unprecedented polyoxygenated 8- and 9-membered rings in one pot. The reactions occur under mild conditions with yields up to 90 %. A perfect regioselectivity is obtained, which can be rationalized through a mechanistic hypothesis that considers 1) the formation of an oxonium ylide, 2) its transformation into an unsaturated acyclic oxocarbenium electrophilic intermediate, and 3) an intramolecular nucleophilic attack in a direct application of Baldwin's rules. Copyright
