198543-54-3Relevant academic research and scientific papers
The use of lithium (α-methylbenzyl)allylamide for the asymmetric synthesis of unsaturated β-amino acid derivatives
Davies, Stephen G.,Fenwick, David R.,Ichihara, Osamu
, p. 3387 - 3391 (1997)
The unsaturated β-amino acid derivatives (3R)-(E)-3-(N-tert- butoxycarbonyl)aminohex-4-enoate and methyl (2S,3S)-3-(N-tert- butoxycarbonyl)-amino-2-bydroxyhex-4-enoate have been synthesised from lithium (s)-(α-methylbenzyl)allylamide and (E,E)-tert-butyl hex-2,4- dienoate. After a highly stereoselective conjugate addition of the lithium amide to the α,β-unsaturated ester, or a highly stereoselective conjugate addition-electrophilic hydroxylation, the adducts are deallylated and the resulting secondary amines converted to either a benzoyl amide or oxazolidinone. The N-α-methylbenzyl group is then removed with either formic acid or using a dissolving metal reduction. These deprotection procedures leave unsaturation in the molecules intact.
Asymmetric synthesis of N-protected syn and anti (E)-3-amino-2-hydroxy- 4-hexenoate: A practical method for the C-α epimerization of anti β-amino- α-hydroxy acids
Brackenridge, Ian,Davies, Stephen G.,Fenwick, David R.,Ichihara, Osamu,Polywka, Mario E. C.
, p. 533 - 540 (2007/10/03)
A practical method to convert anti β-amino-α-hydroxy acids into the corresponding syn esters via the DCC/DMAP-HCl mediated esterification was devised, and methyl (2R,3S)-(E)-3-t-butoxycarbonylamino-2-hydroxy-4-hexenoate 15 was synthesised from the corresponding (2S,3S)-isomer 9 using the epimerization procedure developed. The α- and β-stereogenic centres of 9 were constructed by the Michael addition of a homochiral lithium amide to t- butyl sorbate and subsequent oxidation of the enolate intermediate in one pot.
