Ansa macrolides as molecular workbenches: Stereocontrolled syn additions to E olefins

Article abstract of DOI:10.1002/(SICI)1521-3773(19980619)37:11<1566::AID-ANIE1566>3.0.CO;2-U

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.