Formation of Bicyclic Ethers from Lewis Acid Promoted Cyclizations of Cyclic Oxonium Ions
作者:Pradip K. Sasmal、Martin E. Maier
DOI:10.1021/ol025570d
日期:2002.4.1
Oxacycles carrying a vinyl group and an acetal were extended with a cyclization terminator (vinyl silane or vinyl sulfide) by Suzuki coupling. Treatment with Lewis acid induced cyclization to provide bicyclic ethers in reasonable yields. In the case of the vinyl silane, an ene-like mechanism is preferred, whereas the thioenol ether enters into a Prins-type reaction channel. In one instance, the bicyclic
Asymmetric synthesis of (+)-iso-6-cassine via stereoselective intramolecular amidomercuration
作者:Satwinder Singh、Om V. Singh、Hyunsoo Han
DOI:10.1016/j.tetlet.2007.09.129
日期:2007.11
The first asymmetric synthesis of (+)-iso-6-cassine is described. Lipase-catalyzed resolution, enantioselective Overman rearrangement, and diastereoselective intramolecularamidomercuration were used for the installation of the three stereocenters in (+)-iso-6-cassine, and cross-metathesis was employed for the attachment of the side-chain.