Investigation of an organomagnesium-based [3 + 3] annelation to pyrans and its application in the synthesis of rhopaloic acid A.
A stepwise [3 + 3] annelation reaction has been developed that allows access to pyrans from epoxides. This process involves the addition of an allylmagnesium reagent, itself readily prepared from methallyl alcohol, and a Pd-catalyzed cyclodehydration reaction. The potential of this process to be employed in natural product synthesis has been exemplified by its use in the preparation of rhopaloic acid A.
Brioche
Julien C R
JC
Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, United Kingdom.
Goodenough
Katharine M
KM
Whatrup
David J
DJ
Harrity
Joseph P A
JP
D003500:Cyclization; D008274:Magnesium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry; D011714:Pyrans / Q000138:chemical synthesis / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D017550:Spectroscopy, Fourier Transform Infrared
D011714:Pyrans; C528793:rhopaloic acid A; D010165:Palladium; D008274:Magnesium