Synthesis of (R)-4-Oxo-5-phosphononorvaline, anN-Methyl-D-aspartic Acid Receptor Selective β-Keto Phosphonate

Efficient synthesis of β’-amino-α,β-unsaturated ketones

“…Hence, the addition of enantiopure lithium N -benzyl- N -α-methylbenzylamide to α,β-unsaturated ester 7 followed by hydrogenation to the corresponding primary amine and further protection as a carbamate gave the β-amino methylester 10 . At this stage, the ester function was transformed into the ketophosphonate 13 by treatment with 2.5 equivalents of the lithium anion of diethyl methylphosphonate [22–28] in THF at −78 °C, in moderate to good yields (Scheme 6, Table 1). …”

Aspartyl Phosphonates and Phosphoramidates: The First Synthetic Inhibitors of Bacterial Aspartate-Semialdehyde Dehydrogenase

“…Two diastereomers (A, minor, and B, major) were observed. 1 (2S,4RS)-2-Amino-4-hydroxy-5-phosphono pentanoic acid (16): [32] (2S)-2-Amino-4-oxo-5-phosphono pentanoic acid (13, 93.2 mg, 440 mmol) was dissolved in distilled water (1.5 mL) and cooled to 0 8C. NaBH 4 (40 mg, 98 %, 1.036 mmol) was added to the solution which was then stirred for 2 h at 0 8C.…”

Crystal structures of amino acids: from bond lengths in glycine to metal complexes and high-pressure polymorphs

“…The acidic group may be a carboxylate with modified pK a due to the presence of one or more nearby electron-withdrawing groups of atoms like in BUTFUR (Figure 23), [123] but is more commonly a monosulphate or a monophosphate, as for (R)-4-Oxo-5-phosphononnorvaline (POPJEJ) shown in Figure 4. [124] Likewise, a a(0) zwitterion has the positive charge in the side chain, which will happen when the functional group is a stronger base than the amino group of the polar head. The only example known is the naturally occurring amino acid Arg, which occurs in the a(0) state in its anhydrous form (TAQBIY) [32] as well as in the hydrates of the l-enantiomer (di, ARGIND11) [125] and the racemate (mono-and dihydrate, FUGXIO [126] and WIJNEI [127]).…”