193969-28-7Relevant academic research and scientific papers
Acyclic stereocontrol in the Ireland-Claisen rearrangement of α-branched esters
Qin, Ying-Chuan,Stivala, Craig E.,Zakarian, Armen
, p. 7466 - 7469 (2008/09/18)
(Chemical Equation Presented) To overcome the limitation of the poor diastereoselectivity of the title reaction with α-branched esters, chiral amides were used to generate the enolate intermediates diastereoselectively. The desired rearrangement then took
Optically active 3-amino-2H-azirines as synthons for enantiomerically pure α,α-disubstituted α-amino acids: Syntheses of isovaline synthons and a segment of Trichotoxin A-50
Bucher, Christoph B.,Heimgartner, Heinz
, p. 1903 - 1915 (2007/10/03)
The synthesis of a novel 3-amino-2-methyl-2-[2-(phenylsulfonyl)ethyl]-2H-azirine derivative 12 with a chiral substituent at the amino group is described. Chromatographic separation of the diastereoisomer mixture gave pure diastereoisomers which, after an electrochemical cleavage of the phenylsulfonyl group, yielded the (S)- and (R)-isovalin (Iva) synthons 13a and 13b, respectively. The absolute configuration of the precursor molecule 12b was established by X-ray crystallography. The Iva synthons were successfully used in the synthesis of the C-terminal pentapeptide Z-Leu-Aib-(R)-Iva-Gln-Valol of the peptaibole Trichotoxin A-50 and its epimer.
