Total Synthesis of the Hsp90 Inhibitor Geldanamycin
作者:Hua-Li Qin、James S. Panek
DOI:10.1021/ol800749w
日期:2008.6.1
An enantioselective synthesis of the Hsp90 inhibitor geldanamycin was achieved in 20 linear steps and 2.0% overall yield from 2-methoxyhydroquinone. The synthesis is highlighted by a regio- and stereoselective hydroboration reaction; a Sc(OTf)(3)/Et(3)SiH-mediated pyran ring-opening reaction; an enantioselective crotylation to simultaneously install the C8-C9 (E)-trisubstituted olefin, the C10 and C11 stereocenters; a chelation-controlled asymmetric metallated acetylide addition; and an intramolecular copper(I)-mediated aryl amidation reaction to close the 19-membered macrolactam.
Synthesis of a Cytotoxic Ansamycin Hybrid
作者:Gerrit Jürjens、Andreas Kirschning
DOI:10.1021/ol5011278
日期:2014.6.6
The synthesis of a new ansamycin macrolactam derivative that contains an ansachain based on ansamitocin and an aromatic core related to geldanamycin is reported. The selective introduction of the cyclic carbamoyl group at C7 and C9 relies on a biotransformation using a mutant strain of S. hygroscopicus, the geldanamycin producer. The ansamycin hybrid forms atropisomers that differ in their antiproliferative