Synthesis of Optically Pure (+)-Puraquinonic Acid and Assignment of Absolute Configuration to Natural (−)-Puraquinonic Acid. Use of Radical Cyclization for Asymmetric Generation of a Quaternary Center
作者:Derrick L. J. Clive、Maolin Yu、Mousumi Sannigrahi
DOI:10.1021/jo040115b
日期:2004.6.1
key reactions used to make opticallypure allylic alcohol 40. Radical cyclization of the derived Stork bromo acetals gives lactol ethers 43, which were degraded to generate a quaternary center carrying a methoxycarboxyl group (44 → 47). Compound 47 was converted into (+)-puraquinonic acid; and comparison with a natural sample established that the configuration of the natural compound is 2R (1).