Reaction SMILES: C(OC(=O)[N:10]([CH2:20][C@H:21]([NH:27][C:28](=[O:44])[CH2:29][C:30](=[O:43])[NH:31][C:32]1[CH:37]=[C:36]([C:38]([F:41])([F:40])[F:39])[CH:35]=[C:34]([NH2:42])[CH:33]=1)[C@@H:22]([OH:26])[CH2:23][CH2:24][CH3:25])[CH2:11][C:12]1[CH:17]=[CH:16][C:15]([CH3:18])=[CH:14][C:13]=1[CH3:19])C1C=CC=CC=1.[CH:46](=O)[CH2:47][CH3:48].C([BH3-])#N.[Na+]>CO>[CH3:19][C:13]1[CH:14]=[C:15]([CH3:18])[CH:16]=[CH:17][C:12]=1[CH2:11][NH:10][CH2:20][C@H:21]([NH:27][C:28](=[O:44])[CH2:29][C:30]([NH:31][C:32]1[CH:37]=[C:36]([C:38]([F:41])([F:39])[F:40])[CH:35]=[C:34]([NH:42][CH2:46][CH2:47][CH3:48])[CH:33]=1)=[O:43])[C@@H:22]([OH:26])[CH2:23][CH2:24][CH3:25]
Reactant: CCC=O
Reactant: CCC[C@H](O)[C@H](CN(Cc1ccc(C)cc1C)C(=O)OCc1ccccc1)NC(=O)CC(=O)Nc1cc(N)cc(C(F)(F)F)c1
Agent: [BH3-]C#N
Agent: [Na+]
Solvent: CO
Product: CCCNc1cc(NC(=O)CC(=O)N[C@@H](CNCc2ccc(C)cc2C)[C@@H](O)CCC)cc(C(F)(F)F)c1
Temperature: 25 °C
Reaction time: 0.25 h

Procedure:
A solution of {(2S,3S)-(2-tert-butoxycarbonylamino-3-hydroxy-hex-4-ynyl)}-carbamic acid benzyl ester (1.7 g, 4.8 mmol, prepared as described in WO PCT 0250019) in MeOH (72 mL) was charged with 5% Pd/C, Degussa style (350 mg), stirred under H2 (1 atm) for 12 h at RT, filtered, and concentrated in vacuo. The residue was dissolved in MeOH (47 mL). The resultant solution was charged sequentially with 2,4-dimethylbenzaldehyde (0.66 mL, 4.7 mmol) and sodium cyanoborohydride (360 mg, 5.7 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. The residue was dissolved in THF (66 mL). The resultant solution was charged sequentially with triethylamine (1.2 mL, 9.0 mmol) and dibenzyldicarbonate (1.5 g, 5.4 mmol), stirred for 36 h at RT, quenched with sat. NH4Cl, and extracted twice with EtOAc. The organic extracts were combined, washed with brine, dried (Na2SO4), filtered, and concentrated in vacuo. The residue was purified by flash chromatography to afford (1S,2S)-(1-{[benzyloxycarbonyl-(2,4-dimethyl-benzyl)-amino]-methyl}-2-hydroxy-pentyl)-carbamic acid tert-butyl ester as a clear and colorless oil (2.0 g, 86% yield). MS found: (M+Na)+=507.4. (12b) The compound (1S,2S)-(1-{[benzyloxycarbonyl-(2,4-dimethyl-benzyl)-amino]-methyl}-2-hydroxy-pentyl)-carbamic acid tert-butyl ester (515 mg, 1.06 mmol) was dissolved in CH2Cl2 (12 mL) and treated with TFA (4 mL). The solution was stirred for 3 h and then concentrated in vacuo. The residue was dissolved in benzene and concentrated in vacuo; this procedure was repeated. The resultant amine was dissolved in 15 mL of 2:1 CH2Cl2/DMF. The resultant solution was charged sequentially with N-(3-tert-butoxycarbonylamino-5-trifluoromethyl-phenyl)-malonamic acid (400 mg, 1.1 mmol, see examples 8 and 1), N,N-diisopropylethylamine (0.96 mL, 5.5 mmol) and HATU (504 mg, 1.3 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 (3-{2-[(1S,2S)-1{[benzyloxycarbonyl-(2,4-dimethyl-benzyl)-amino]-methyl}-2-hydroxy-pentylcarbamoyl]-acetylamino}-5-trifluoromethyl-phenyl)-carbamic acid tert-butyl ester (577 mg, 75% yield). MS found: (M+Na)+=751.4. (12c) The compound (3-{2-[(1S,2S)-1-{[benzyloxycarbonyl-(2,4-dimethyl-benzyl)-amino]-methyl}-2-hydroxy-pentylcarbamoyl]-acetylamino}-5-trifluoromethyl-phenyl)-carbamic acid tert-butyl ester (577 mg, 0.79 mmol) was dissolved in CH2Cl2 (12 mL) and treated with TFA (4 mL). The solution was stirred for 3 h and then concentrated in vacuo. The residue was dissolved in benzene and concentrated in vacuo; this procedure was repeated to provide {(2S,3S)-2-[2-(3-amino-5-trifluoromethyl-phenylcarbamoyl)-acetylamino]-3-hydroxyhexyl}-(2,4-dimethyl-benzyl)-carbamic acid benzyl ester (100% yield). MS found: (M+H)+=629.4. (12d) A solution of {(2S,3S)-2-[2-(3-amino-5-trifluoromethyl-phenylcarbamoyl)-acetylamino]-3-hydroxyhexyl}-(2,4-dimethyl-benzyl)-carbamic acid benzyl ester (97 mg, 0.15 mmol) in MeOH (3 mL) was charged with propionaldehyde (0.01 mL, 0.15 mmol), stirred for 15 min at RT, and then charged with sodium cyanoborohydride (12 mg, 0.19 mmol). The reaction was stirred at RT for 12 h, concentrated in vacuo, and dissolved in EtOAc. The resultant solution washed successively with water, sat. NaHCO3, water, and brine. The organic phase was dried (Na2SO4), filtered, and concentrated in vacuo. The residue was dissolved in MeOH (3 mL). This solution was charged with 5% Pd/C, Degussa style (11 mg), stirred under H2 (1 atm) for 12 h at RT, 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)+=537.4.