Acetonitrile → N-[2-(1,1-Dimethylethoxy)-2-oxoethyl]-N-(2-hydroxyethyl)-L-tryptophan 1,1-dimethylethyl ester

HRID 1634917Notes

Reaction equation

[CH3:1][C:2]([O:5][C:6](=[O:27])[C@H:7]([CH2:17][C:18]1[C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[NH:20][CH:19]=1)[NH:8][CH2:9][C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])([CH3:4])[CH3:3].[O-]S(C(F)(F)F)(=O)=O.[Yb+3].[O-]S(C(F)(F)F)(=O)=O.[O-:45]S(C(F)(F)F)(=O)=O.[CH3:53][C:54]#N>O.C1OC1>[CH3:4][C:2]([O:5][C:6](=[O:27])[C@H:7]([CH2:17][C:18]1[C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[NH:20][CH:19]=1)[N:8]([CH2:9][C:10]([O:12][C:13]([CH3:14])([CH3:15])[CH3:16])=[O:11])[CH2:53][CH2:54][OH:45])([CH3:1])[CH3:3]

Participants

Conditions

Temperature: -80 °C

Procedure

A jacketed reactor is loaded with a solution of N-[2-(1,1-dimethylethoxy)-2-oxoethyl]-L-tryptophan 1,1-dimethylethyl ester (5 g; 13.35 mol) prepared at point B, in CH3CN (25 mL). To the solution cooled to −80° C. is added ethylene oxide (13 mL; 0.26 mol) and ytterbium triflate (0.83 g; 1.34 mol). The mixture is then slowly warmed to room temperature then, after 15 hours, diluted with water (50 mL) and extracted with Et2O (3×50 mL). The organic phases are evaporated to dryness to obtain a crude which is purified by flash chromatography (eluent n-hexane/EtOAc 7:3) to give the desired product as a pale yellow oil (4.32 g; 10.32 mol).

Workup

temperatureThe mixture is then slowly warmed to room temperature
extractionextracted with Et2O (3×50 mL)
customThe organic phases are evaporated to dryness
customto obtain a crude which
customis purified by flash chromatography (eluent n-hexane/EtOAc 7:3)

Sources & evidence

ORD record: ord-8df0f22d23444749aaf8b11c43e695f2
Source dataset: uspto-grants-2003_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06509324B1

Reaction notes

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