1402050-34-3Relevant academic research and scientific papers
Total synthesis of (-)-caprazamycin a
Nakamura, Hugh,Yasui, Motohiro,Yokouchi, Shinsuke,Takemoto, Yoshiji,Tsukano, Chihiro,Igarashi, Masayuki
, p. 3136 - 3139 (2015)
Caprazamycin A has significant antibacterial activity against Mycobacterium tuberculosis (TB). The first total synthesis is herein reported and features a) the scalable preparation of the syn-β-hydroxy amino acid with a thioureacatalyzed diastereoselectiv
Total Synthesis of Caprazamycin A: Practical and Scalable Synthesis of syn-β-Hydroxyamino Acids and Introduction of a Fatty Acid Side Chain to 1,4-Diazepanone
Nakamura, Hugh,Tsukano, Chihiro,Yoshida, Takuma,Yasui, Motohiro,Yokouchi, Shinsuke,Kobayashi, Yusuke,Igarashi, Masayuki,Takemoto, Yoshiji
supporting information, p. 8527 - 8540 (2019/06/04)
The first total synthesis of caprazamycin A (1), a representative liponucleoside antibiotic, is described. Diastereoselective aldol reactions of aldehydes 12 and 25-27, derived from uridine, with diethyl isocyanomalonate 13 and phenylcarbamate 21 were investigated using thiourea catalysts 14 or bases to synthesize syn-β-hydroxyamino acid derivatives. The 1,4-diazepanone core of 1 was constructed using a Mitsunobu reaction, and the fatty acid side chain was introduced using a stepwise sequence based on model studies. Notably, global deprotection was realized using palladium black and formic acid without hydrogenating the olefin in the uridine unit.
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.
Studies on catalytic enantioselective total synthesis of caprazamycin B: Construction of the western zone
Gopinath, Purushothaman,Watanabe, Takumi,Shibasaki, Masakatsu
, p. 9260 - 9267 (2013/01/15)
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.
