Ansa Macrolides as Molecular Workbenches: Stereocontrolledsyn Additions toE olefins
摘要:
Fixed on an aromatic platform in a conformationally defined way, acyclic (E)-alkenes can be considered gripped on a molecular workbench. The olefinic ansa-macrolides formed in this way are shielded on one face. On epoxidation and dihydroxylation [Eq. (1)] the attack on the double bond takes place diastereoselectively from outside the ring, and the ansa chain can subsequently be cleaved from the workbench by mild hydrogenolysis. Bn=benzyl, NMO=N-methylmorpholin-N-oxide.
Ansa Macrolides as Molecular Workbenches: Stereocontrolledsyn Additions toE olefins
摘要:
Fixed on an aromatic platform in a conformationally defined way, acyclic (E)-alkenes can be considered gripped on a molecular workbench. The olefinic ansa-macrolides formed in this way are shielded on one face. On epoxidation and dihydroxylation [Eq. (1)] the attack on the double bond takes place diastereoselectively from outside the ring, and the ansa chain can subsequently be cleaved from the workbench by mild hydrogenolysis. Bn=benzyl, NMO=N-methylmorpholin-N-oxide.
Fixed on an aromatic platform in a conformationally defined way, acyclic (E)-alkenes can be considered gripped on a molecular workbench. The olefinic ansa-macrolides formed in this way are shielded on one face. On epoxidation and dihydroxylation [Eq. (1)] the attack on the double bond takes place diastereoselectively from outside the ring, and the ansa chain can subsequently be cleaved from the workbench by mild hydrogenolysis. Bn=benzyl, NMO=N-methylmorpholin-N-oxide.