Author/Authors :
Shigenobu Nishiguchi، نويسنده , , Magne O. Sydnes، نويسنده , , Akihiro Taguchi، نويسنده , , Thomas Regnier، نويسنده , , Tetsuya Kajimoto، نويسنده , , Manabu Node، نويسنده , , Yuri Yamazaki، نويسنده , , Fumika Yakushiji، نويسنده , , Yoshiaki Kiso، نويسنده , , Yoshio Hayashi، نويسنده ,
Abstract :
(+)-Negamycin was prepared in 13 steps in an overall yield of 31% from commercially available ethyl (R)-(+)-4-chloro-3-hydroxybutanoate. The key step in the reaction sequence was a highly stereoselective asymmetric Michael addition of chiral amine (−)-21 [(1S,2R)-(−)-2-methoxybornyl-10-benzylamine] into the α,β-unsaturated carbonyl moiety of key intermediate 8, thus establishing the second chiral center in (+)-negamycin. 5-epi-Negamycin was also prepared in a similar fashion.
