Transformation of Carbonates into Sulfones at the Benzylic Position via Palladium-Catalyzed Benzylic Substitution
作者:Ryoichi Kuwano、Yutaka Kondo、Tsuyoshi Shirahama
DOI:10.1021/ol0509787
日期:2005.7.1
The nucleophilic substitution of benzylic carbonates with sodium arenesulfinates was catalyzed by the palladium complex generated in situ from [Pd(eta(3)-C3H5)Cl](2) and DPEphos [bis(2-diphenylphosphinophenyl)ether]. The catalytic reaction proceeded in DMSO at 80 degrees C and gave a variety of benzylic sulfones in high yields.
Synthesis of (−)-Calicoferol B
作者:Douglass F. Taber、Qin Jiang、Bei Chen、Wei Zhang、Carlton L. Campbell
DOI:10.1021/jo020103v
日期:2002.7.1
The first total synthesis of (-)-calicoferol B (III) is described. The cyclozirconation product I, prepared in enantiomerically pure form, was converted into the CD ring chiron II. This was coupled with the aromatic A-ring, and then the side chain was constructed with control of relative and absoluteconfiguration to complete the total synthesis of III. The first total synthesis of (-)-calicoferol