(2R)-5-amino-2-[(2-methylpropan-2-yl)oxycarbonylamino]pentanoic acid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 696 mg (3.0 mmol) of Boc-D-Ornithine (as a 1M solution in ethanol) was added 551.5 mg (3.30 mmol) of 2-fluoro-3-nitrotoluene and 3 ml (3 mmol) of 1N sodium hydroxide. The reaction was heated to reflux for 24 hours. The reaction was concentrated/n vacuo. The product was purified by flash chromatography with acetonitrile/acetic acid/water 6/1/1. The product (620 mg, 61% yield) was obtained was a yellow oil. mp>258° C. (dec.). MS (FAB) M/Z: 268 (M+H). 1H NMR (300 MHz, CDCl3) δ: 1.7-2.0 (m, 4H), 2.1 (s, 9H), 2.45 (s, 3H), 3.40 (t, 2H), 4.00 (t, 1H), 6.60 (td, 1H), 7.10 (dd, 1H), 8.00 (dd, 1H). The reaction was heated to reflux for 24 hours The reaction was concentrated/n vacuo The product was purified by flash chromatography with acetonitrile/acetic acid/water 6/1/1

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of Boc-D-Orn-OH (0.50 g, 2.2 mmol) in aqueous NaOH (1M, 5 mL) at 0° C. was added benzyl chloroformate (0.37 mL, 2.6 mmol, 1.2 equiv) followed by aqueous NaOH (1M, 5 mL). After stirring for 2 hours at room temperature, the reaction mixture was poured to separatory funnel and extracted with ether. The aqueous layer was acidified to pH 3 with aqueous 10% citric acid and extracted with ethyl acetate. The combined organic layer was washed with brine, dried with Na2SO4, filtered and concentrated in vacuo to afford compound 3.2.1a (0.57 g, 72%) which was used for the next step without further purification. MS m/z (M+Na) 389.2. 1H NMR (400 MHz, DMSO-d6) 12.37 (br-s, 1H), 7.35-7.25 (m, 5H), 7.20 (t, J=5.31 Hz, 1H), 7.01 (d, J=8.02 Hz, 1H), 4.97 (s, 2H), 3.83-3.77 (m, 1H), 2.94 (dd, 2H), 1.67-1.56 (m, 1H), 1.53-1.37 (m, 3H), 1.34 (s, 9H). the reaction mixture was poured to separatory funnel extracted with ether extracted with ethyl acetate The combined organic layer was washed with brine dried with Na2SO4 filtered concentrated in vacuo to afford compound 3.2.1a (0.57 g, 72%) which was used for the next step without further purification