Transannular nitrone cycloaddition. A stereocontrolled entry to the spirocyclic core of pinnaic acid.
[figure: see text] Thermolysis of lactone 18 initiated a stereospecific transannular nitrone-olefin [3 + 2] cycloaddition to yield tetracycle 19. Methanolysis followed by reductive cleavage of the isoxazolidine yielded 20, representing the azaspirocyclic core of pinnaic acid (1).
White
J D
JD
Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, USA. james.white@orst.edu
Blakemore
P R
PR
Korf
E A
EA
Yokochi
A F
AF
D000470:Alkaloids / Q000138:chemical synthesis*; D018360:Crystallography, X-Ray; D009589:Nitrogen Oxides / Q000737:chemistry*; D013141:Spiro Compounds / Q000138:chemical synthesis*; D013237:Stereoisomerism
D000470:Alkaloids; D009589:Nitrogen Oxides; D013141:Spiro Compounds; C015388:nitrones; C412665:pinnaic acid