618892-50-5Relevant articles and documents
Diastereoselective synthesis of 2-amino-4-phosphonobutanoic acids by conjugate addition of lithiated schoellkopf's bislactim ethers to vinylphosphonates
Ruiz, Maria,Fernandez, M. Carmen,Diaz, Aniana,Quintela, Jose M.,Ojea, Vicente
, p. 7634 - 7645 (2007/10/03)
Conjugate additions of lithiated bislactim ethers derived from cyclo-[Gly-Val] and cyclo-[Ala-Val] to α, β, or α,β -substituted vinylphosphonates allow direct and stereoselective access to a variety of 3- or 4-monosubstituted and 2,3-, 2,4-, or 3,4-disubstituted 2-amino-4-phosphonobutanoic acids (AP4 derivatives) in enantiomerically pure form. The relative stereochemistry was assigned by X-ray diffraction analysis or NMR study of 1,2-oxaphosphorinane derivatives. Competitive eight-membered "compact" and "relaxed" transition-state structures are invoked to rationalize the stereochemical outcome of the conjugate additions.
Conjugate additions of E-alkenylphosphonates to lithiated Schollkopf's bislactim ether: Stereocontrolled access to anti 2-amino-3-substituted-4-phosphonobutanoic acids
Ojea, Vicente,Fernandez, Ma. Carmen,Ruiz, Maria,Quintela, Jose Ma.
, p. 5801 - 5804 (2007/10/03)
Highly face-selective Michael adition of lithiated Schollkopf's bislactim ether (derived from cyclo-[L-val-gly], 7) to E-alkenylphosphonates 2a-d and 1,3-butadienylphosphonate 2e allows a direct and stereocontrolled access to the excitatory amino acid analogues 2,3-anti-2-amino-3-substituted-4-phosphonobutanoic acids 14a-d and 2-amino-6-phosphono-4-hexenoic acid 15. The relative stereochemistry was assigned from a NMR study of cyclic derivatives 16, 17 and 19.
