TY - JOUR
T1 - Dehydrative cyclization catalyzed by the combination of molybdenum(VI) oxides and benzoic acids
T2 - First synthesis of the antitumour substance BE-70016
AU - Sakakura, Akira
AU - Umemura, Shuhei
AU - Kondo, Rei
AU - Ishihara, Kazuaki
PY - 2007/3
Y1 - 2007/3
N2 - The dehydrative cyclization of N-(o-hydroxybenzoyl)threonine derivative la is efficiently promoted by the combined use of molybdenum(VI) oxides and benzoic acids bearing electron-with-drawing substituents. In the presence of ammonium molybdate [(NH4)2MoO4, 10 mol%] and penta-fluorobenzoic acid (C6F5CO2H; 10 mol%), dehydrative cyclization of la was conducted in toluene under azeotropic reflux conditions to give 2-(o-hydroxyphenyl)oxazoline 2a in 76% yield. Furthermore, the first total synthesis of the antitumour substance BE-70016 was achieved using the catalytic dehydrative cyclization of 1a as a key reaction.
AB - The dehydrative cyclization of N-(o-hydroxybenzoyl)threonine derivative la is efficiently promoted by the combined use of molybdenum(VI) oxides and benzoic acids bearing electron-with-drawing substituents. In the presence of ammonium molybdate [(NH4)2MoO4, 10 mol%] and penta-fluorobenzoic acid (C6F5CO2H; 10 mol%), dehydrative cyclization of la was conducted in toluene under azeotropic reflux conditions to give 2-(o-hydroxyphenyl)oxazoline 2a in 76% yield. Furthermore, the first total synthesis of the antitumour substance BE-70016 was achieved using the catalytic dehydrative cyclization of 1a as a key reaction.
KW - Catalysis
KW - Dehydrative cyclization
KW - Molybdenum(VI) oxide
KW - Oxazolines
KW - Pentafluorobenzoic acid
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U2 - 10.1002/adsc.200600550
DO - 10.1002/adsc.200600550
M3 - Article
AN - SCOPUS:34547191755
SN - 1615-4150
VL - 349
SP - 551
EP - 555
JO - Advanced Synthesis and Catalysis
JF - Advanced Synthesis and Catalysis
IS - 4-5
ER -