Chemo- and stereoselective dirhodium(II)-catalyzed C-H insertion reaction of 5,6-dioxygenated 2-diazo-3-oxohexanoates: Synthesis of an optically active highly functionalized cyclopentane

✍ Scribed by Takayuki Yakura; Akiharu Ueki; Tsuyoshi Kitamura; Kenji Tanaka; Masatake Nameki; Masazumi Ikeda

• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 667 KB
• Volume: 55
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(99)00369-5

✦ Synopsis

Methyl (S)-(x-diazo-2,2-dimethyl-13-oxo-l,3-diox01ane-2-butanoate (4), upon treatment with dirhodium(II) tetmacetate in refluxing dichioromethane, gave methyl (1S,5S)-2,2-dimethyl-7-oxo-3,8dioxabicyclo[3.2.1 ]octane-l-carboxylate (5) via oxonium ylide formation/1,2-shift. On the other hand, a similar treatment of methyl (S)-5,6-bis[tert-butyldimethylsilylgFBDMS)oxy]-2-diazo-3-oxohexanoate (9a) afforded the C-H insertion product 10 which was directly reduced with lithium aluminum hydride to give stereoselectively (1R,2R,3S,5R)-2,3-bis(TBDMSoxy)-5-hydroxycyclopentanemethanol (13) in 52% yield from 9a.