Reaction SMILES: [CH2:1]([O:8][C:9](=[O:19])[NH:10][CH2:11][C@H:12]([NH2:18])[C@@H:13]([OH:17])[C:14]#[C:15][CH3:16])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:20]([O:26][CH2:27][C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1)(=[O:25])[CH2:21][C:22]([O-])=[O:23].C(N(CC)C(C)C)(C)C.CN(C(ON1N=NC2C=CC=NC1=2)=[N+](C)C)C.F[P-](F)(F)(F)(F)F>C(Cl)Cl.CN(C=O)C>[CH2:27]([O:26][C:20](=[O:25])[CH2:21][C:22]([NH:18][C@@H:12]([CH2:11][NH:10][C:9]([O:8][CH2:1][C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1)=[O:19])[C@@H:13]([OH:17])[C:14]#[C:15][CH3:16])=[O:23])[C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1
Reactant: O=C([O-])CC(=O)OCc1ccccc1
Reactant: CC#C[C@H](O)[C@@H](N)CNC(=O)OCc1ccccc1
Agent: CN(C)C(On1nnc2cccnc21)=[N+](C)C
Agent: F[P-](F)(F)(F)(F)F
Solvent: CCN(C(C)C)C(C)C
Solvent: ClCCl
Solvent: CN(C)C=O
Product: CC#C[C@H](O)[C@H](CNC(=O)OCc1ccccc1)NC(=O)CC(=O)OCc1ccccc1
Temperature: 25 °C
Reaction time: 12 h
Yield: 90 %

Procedure:
The compound [(2S,3S)-2-amino-3-hydroxy-hex-4-ynyl]-carbamic acid benzyl ester (1.45 g, 3.8 mmol, prepared as described in WO PCT 0250019) was dissolved in 38 mL of 1:1 CH2Cl2/DMF. The resultant solution was charged sequentially with mono-benzyl malonate (745 mg, 3.8 mmol), N,N-diisopropylethylamine (6.7 mL, 38 mmol) and HATU (1.75 g, 4.6 mmol). The mixture was stirred for 12 h at RT, concentrated in vacuo, and partitioned between EtOAc and sat. NH4Cl. The aqueous phase was extracted with EtOAc (1×). The combined organic extracts were washed with sat. NaHCO3 and brine, dried (Na2SO4), filtered, and concentrated in vacuo. The residue was purified by flash chromatography to provide N-[(1S,2S)-1-(benzyloxycarbonylamino-methyl)-2-hydroxy-pent-3-ynyl]-malonamic acid benzyl ester (1.5 g, 91% yield). MS found: (M+H)+=439.4. The entirity of this material was dissolved in THF (18 mL). This solution was charged sequentially with MeOH (6 mL) and aq. LiOH (84 mg LiOH in 6 mL water) and stirred for 12 h at RT. The mixture was concentrated in vacuo, and the residue was lyophilized from 1:1 acetonitrile/water to provide the lithium salt of N-[(1S,2S)-1-(benzyloxycarbonylamino-methyl)-2-hydroxy-pent-3-ynyl]-malonamic acid. MS found: (M+H)+=355.3. (21b) The compound 3-nitro-5-trifluoromethylbenzoic acid (500 mg, 2.1 mmol) was dissolved in 20 mL of 1:1 CH2Cl2/DMF. The resultant solution was charged sequentially with dimethylamine hydrochloride (174 mg, 2.1 mmol), N,N-diisopropylethylamine (3.7 mL, 21 mmol) and HATU (970 mg, 2.6 mmol). The mixture was stirred for 12 h at RT, concentrated in vacuo, and partitioned between EtOAc and sat. NH4Cl. The aqueous phase was extracted with EtOAc (1×). The combined organic extracts were washed with sat. NaHCO3 and brine, dried (Na2SO4), filtered, and concentrated in vacuo. A portion (107 mg) of this product was dissolved in MeOH (6 mL). This solution was charged with 5% Pd/C, Degussa style (21 mg), stirred under H2 (1 atm) for 12 h at RT, filtered, and concentrated in vacuo. The residue was dissolved in 6 mL of 1:1 CH2Cl2/DMF. The resultant solution was charged sequentially with the lithium salt of N-[(1S,2S)-1-(benzyloxycarbonylamino-methyl)-2-hydroxy-pent-3-ynyl]-malonamic acid (141 mg, 0.4 mmol, see procedure 21a), N, N-diisopropylethylamine (0.35 mL, 2.0 mmol) and HATU (182 mg, 0.5 mmol). The mixture was stirred for 12 h at RT, concentrated in vacuo, and partitioned between EtOAc and sat. NH4Cl. The aqueous phase was extracted with EtOAc (1×). The combined organic extracts were washed with sat. NaHCO3 and brine, dried (Na2SO4), filtered, and concentrated in vacuo. The residue was purified by flash chromatography to afford {(2S,3S)-2-[2-(3-dimethylcarbamoyl-5-trifluoromethyl-phenylcarbamoyl)-acetylamino]-3-hydroxy-hex-4-ynyl}-carbamic acid benzyl ester as a colorless oil (186 mg, 81% yield). MS found: (M+Na)+=585.3. (21c) A solution of {(2S,3S)-2-[2-(3-dimethylcarbamoyl-5-trifluoromethyl-phenylcarbamoyl)-acetylamino]-3-hydroxy-hex-4-ynyl}-carbamic acid benzyl ester (186 mg, 0.33 mmol) in MeOH (6 mL) was charged with 5% Pd/C, Degussa style (37 mg), stirred under H2 (1 atm) for 12 h at RT, filtered, and concentrated in vacuo. The residue was dissolved in MeOH (6 mL). The resultant solution was charged sequentially with 2,4-dimethylbenzaldehyde (46 mg, 0.33 mmol) and sodium cyanoborohydride (25 mg, 0.4 mmol), stirred for 12 h at RT, quenched with sat. NaHCO3, and extracted twice with EtOAc. The organic extracts were combined, washed with brine, dried (Na2SO4), filtered, and concentrated in vacuo. Purification of the residue by reverse-phase HPLC provided the title compound as a white powder after lyopholization. MS found: (M+H)+=551.3.