�ber einen neuartigen synthetischen Zugang zu ?,?-unges�ttigten ?-Aminocarbons�uren
摘要:
A New Synthetic Route to β,α‐Unsaturated α‐Amino AcidsA versatile new synthetic pathway for the preparation of βγ‐unsaturated α‐amino acids (1) is presented. Cu(I)‐catalyzed addition of ethyl isocyanoacetate (2) to α‐chloro carbonyl compounds (3) gives 5‐chloroalkyl‐2‐oxazolin‐4‐carboxylates (4) in high yields. A reductive elimination on 4 by means of zinc yields the N‐formyl derivatives of βγ‐unsaturated α‐amino carboxylates (5), which on acid hydrolysis lead to the free amino acids 1. The five different βγ‐dehydro‐α‐amono acids 1b‐1f have been prepared by this method.
Exploration of the Molecular Origin of the Azinomycin Epoxide: Timing of the Biosynthesis Revealed
摘要:
Streptomyces sahachiroi whole cell feeding experiments, utilizing putative precursors labeled with stable isotopes, established that the epoxide unit of the DNA cross-linked agents, azinomycin A and B, proceeds via a valine-dependent pathway and that hydroxylation and dehydration precedes formation of the terminal epoxide. Sodium 3-methyl-2-oxobutenoate, formed through a transimination reaction, was shown to be the penultimate precursor incorporated into the azinomycin epoxide.
HEINZER, F.;BELLUS, D., HELV. CHIM. ACTA, 1981, 64, N 7, 2279-2297
作者:HEINZER, F.、BELLUS, D.
DOI:——
日期:——
�ber einen neuartigen synthetischen Zugang zu ?,?-unges�ttigten ?-Aminocarbons�uren
作者:Franz Heinzer、Daniel Bellu?
DOI:10.1002/hlca.19810640734
日期:1981.11.4
A New Synthetic Route to β,α‐Unsaturated α‐Amino AcidsA versatile new synthetic pathway for the preparation of βγ‐unsaturated α‐amino acids (1) is presented. Cu(I)‐catalyzed addition of ethyl isocyanoacetate (2) to α‐chloro carbonyl compounds (3) gives 5‐chloroalkyl‐2‐oxazolin‐4‐carboxylates (4) in high yields. A reductive elimination on 4 by means of zinc yields the N‐formyl derivatives of βγ‐unsaturated α‐amino carboxylates (5), which on acid hydrolysis lead to the free amino acids 1. The five different βγ‐dehydro‐α‐amono acids 1b‐1f have been prepared by this method.
Exploration of the Molecular Origin of the Azinomycin Epoxide: Timing of the Biosynthesis Revealed
作者:Vasudha Sharma、Gilbert T. Kelly、Coran M. H. Watanabe
DOI:10.1021/ol8018852
日期:2008.11.6
Streptomyces sahachiroi whole cell feeding experiments, utilizing putative precursors labeled with stable isotopes, established that the epoxide unit of the DNA cross-linked agents, azinomycin A and B, proceeds via a valine-dependent pathway and that hydroxylation and dehydration precedes formation of the terminal epoxide. Sodium 3-methyl-2-oxobutenoate, formed through a transimination reaction, was shown to be the penultimate precursor incorporated into the azinomycin epoxide.