Synthesis of Pyrrolo[2,3-d][1,2,3]thiadiazole-6-carboxylates via the Hurd-Mori Reaction. Investigating the Effect of the N-Protecting Group on the Cyclization
A convenient and new approach to the synthesis of ω-heterocyclic amino acids from carboxy lactams through ring-chain-transformation. Part 2: Synthesis of (2R)-/(2S)-2-aminomethyl-3-(1-aryl-/1,5-diaryl-1H-pyrazol-3-yl)-propionic acid
作者:Rakesh K. Singh、Neelima Sinha、Sanjay Jain、Mohammad Salman、Fehmida Naqvi、Nitya Anand
DOI:10.1016/j.tet.2005.07.018
日期:2005.9
and short path synthesis of optically pure ω-heterocyclic-β-amino acids has been achieved from (1R,3R)- and (1R,3S)-5-oxo-1-(1-phenyl-ethyl)-pyrrolidine-3-carboxylic acid methyl ester. The key step of the synthesis involves a regiospecific ring-chain-transformation of the enaminones when subjected to 1,2-binucleophilic attacks. The method is illustrated by the synthesis of (2R)-/(2S)-2-aminomethyl-3-(1-aryl-/1
Hetero-1,3-dipolar cycloadditions of dithiolane-isocyanate imminium methylides: A novel route to 1,3-oxazolidine- and thiazolidine-2-thiones
作者:Colin W.G. Fishwick、Richard J. Foster、Robin E. Carr
DOI:10.1016/0040-4039(95)02249-x
日期:1996.1
Dithiolane- isocyanate imminium methylides which are a new type of azomethine methylide-derived 1,3-dipole undergo efficient and regioselective cycloaddition to conjugated carbonyls and thiocarbonyls to yield predominantly 1,3-oxazolidine- and thiazolidine-2-thiones formed from the initial cycloadducts via loss of thurane.