One-Pot Multistep Bohlmann−Rahtz Heteroannulation Reactions: Synthesis of Dimethyl Sulfomycinamate
摘要:
The synthesis of dimethyl sulfomycinamate, the acidic methanolysis product of the sulfomycin family of thiopeptide antibiotics, from methyl 2-oxo-4-(trimethylsilyl)but-3-ynoate is achieved in a 2,3,6-trisubstituted pyridine synthesis that proceeds with total regiocontrol in 13 steps by the Bohlmann-Rahtz heteroannulation of a 1-(oxazol-4-yl)enamine or in 12 steps and 9% yield by three-component cyclocondensation with N-[3-oxo-3-(oxazol-4-yl)propanoyl]serine and ammonia in ethanol.
Dimethyl sulfomycinamate, the oxazole-thiazole-pyridine product generated in the methanolysis of the thiopeptide antibiotic sulfomycin 1, is prepared in 13 steps and 8% overall yield by the Bohlmann-Rahtz heteroannulation of 1-(oxazol-4-yl)enamines and methyl 4-(trimethylsilyl)2-oxobut-3-ynoate.
The ethyl oxazole-4-carboxylate was directly and regioselectively alkenylated, benzylated and alkylated with alkenyl-, benzyl-, allyl- and alkylhalides in the presence of catalytic amounts of palladiumacetate with caesium carbonate using Buchwald's JohnPhos ligand.
作者:Mark C. Bagley、James W. Dale、Xin Xiong、Justin Bower
DOI:10.1021/ol0357144
日期:2003.11.1
Dimethyl sulfomycinamate, the oxazole-thiazole-pyridine product generated in the methanolysis of the thiopeptide antibiotic sulfomycin 1, is prepared in 13 steps and 8% overall yield by the Bohlmann-Rahtz heteroannulation of 1-(oxazol-4-yl)enamines and methyl 4-(trimethylsilyl)2-oxobut-3-ynoate.
One-Pot Multistep Bohlmann−Rahtz Heteroannulation Reactions: Synthesis of Dimethyl Sulfomycinamate
作者:Mark C. Bagley、Krishna Chapaneri、James W. Dale、Xin Xiong、Justin Bower
DOI:10.1021/jo048106q
日期:2005.2.1
The synthesis of dimethyl sulfomycinamate, the acidic methanolysis product of the sulfomycin family of thiopeptide antibiotics, from methyl 2-oxo-4-(trimethylsilyl)but-3-ynoate is achieved in a 2,3,6-trisubstituted pyridine synthesis that proceeds with total regiocontrol in 13 steps by the Bohlmann-Rahtz heteroannulation of a 1-(oxazol-4-yl)enamine or in 12 steps and 9% yield by three-component cyclocondensation with N-[3-oxo-3-(oxazol-4-yl)propanoyl]serine and ammonia in ethanol.