1402050-29-6Relevant articles and documents
Studies on catalytic enantioselective total synthesis of caprazamycin B: Construction of the western zone
Gopinath, Purushothaman,Watanabe, Takumi,Shibasaki, Masakatsu
, p. 9260 - 9267,8 (2012/12/11)
We describe a simple and convenient synthesis of the western zone of caprazamycin B using two catalytic asymmetric reactions as key elements of our approach. Desymmetrization of 3-methylglutaric anhydride with the (S)-Ni 2-(Schiff base) complex as a catalyst furnished the chiral hemiester, and a thioamide-aldol reaction with mesitylcopper, (R,R)-Ph-BPE, and 2,2,5,7,8-pentamethylchromanol as a catalyst furnished the β-hydroxy thioamide in good yield and enantioselectivity. On further transformation, the thioamide functionality was converted to the corresponding β-hydroxy ester. Finally, a convergent synthesis of the western zone of caprazamycin B was achieved by connecting the hemiester, the β-hydroxy ester, and the 2,3,4-tri-O-methyl-l-rhamnose fragments.
