Total synthesis of (+)-isoschizandrin utilizing a samarium(II) iodide-promoted 8-endo ketyl-olefin cyclization.
The 13-step synthesis of (+)-isoschizandrin reported herein features a samarium(II) iodide-promoted 8-endo ketyl-olefin coupling to assemble the eight-membered ring present in the target concomitantly with the required functionality and stereochemistry. In constructing (+)-isoschizandrin as a single atropisomer, the synthesis utilizes a kinetic resolution of a seven-membered lactone using a CBS-oxazaborolidine.
Molander
Gary A
GA
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA. gmolandr@sas.upenn.edu
George
Kelly M
KM
Monovich
Lauren G
LG
D000475:Alkenes / Q000737:chemistry; D001372:Aza Compounds / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry; D003500:Cyclization; D034242:Cyclooctanes / Q000138:chemical synthesis* / Q000737:chemistry; D007454:Iodides / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D007783:Lactones / Q000737:chemistry; D017705:Lignans / Q000138:chemical synthesis* / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000138:chemical synthesis*; D012493:Samarium / Q000737:chemistry*; D032141:Schisandra / Q000737:chemistry*; D013237:Stereoisomerism
D000475:Alkenes; D001372:Aza Compounds; D001896:Boron Compounds; D034242:Cyclooctanes; D007454:Iodides; D007659:Ketones; D007783:Lactones; D017705:Lignans; D011083:Polycyclic Compounds; C482833:isoschizandrin; D012493:Samarium; C011105:schizandrin