Development of a Nazarov Cyclization/Wagner−Meerwein Rearrangement Sequence for the Stereoselective Synthesis of Spirocycles

• Published in: Journal of the American Chemical Society Vol. 129; no. 26; pp. 8060 - 8061
• Main Authors: Huang, Jie, Frontier, Alison J
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 04.07.2007; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Multidisciplinary; Physical Sciences; Science & Technology; ORGANIC-SYNTHESIS; KETONES; INTERMEDIATE
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0716148

A stereoselective Nazarov cyclization/Wagner−Meerwein rearrangement sequence for the synthesis of spirocyclic compounds was developed. While a range of different substrate types engaged in the cyclization/rearrangement sequence, it was found that different substrates underwent different reaction pathways. Depending on the substitution pattern of the substrate, the sequence was terminated by either a hydride shift or the shift of a vinyl or aryl group. It was also possible to install adjacent quaternary stereocenters using this protocol. The efficiency of the Wagner−Meerwein rearrangement was found to be dependent upon both the type and the amount of promoter used to generate the intermediate oxyallyl cation.