Sequenced reactions with samarium(II) iodide. Sequential intramolecular Barbier cyclization/Grob fragmentation for the synthesis of medium-sized carbocycles.
Samarium(II) iodide was used to access eight-, nine-, and ten-membered carbocycles via a domino reaction composed of a cyclization/fragmentation process. 2-(Iodoalkyl)-, 2-(iodomethyl)allyl-, and 2-(2-iodomethyl)benzyl-2-methyl-3-(methanesulfonyloxy)cycloalkanones were subjected to Barbier-type reductive coupling conditions. Intermediate cycloalkanedione derivatives were also treated under similar conditions, providing bicyclic hydroxy ketones with complete diastereoselectivity and high yields. This method represents a general and efficient approach to a variety of highly functionalized, stereodefined carbocycles.
Molander
G A
GA
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA. gmolandr@sas.upenn.edu
Le Huérou
Y
Y
Brown
G A
GA
D000473:Alkanes / Q000737:chemistry*; D000478:Alkylation; D003500:Cyclization; D007454:Iodides / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry; D010084:Oxidation-Reduction; D012493:Samarium / Q000737:chemistry*
D000473:Alkanes; D007454:Iodides; D007659:Ketones; D012493:Samarium; C409809:samarium diiodide