Tert-Butylamine → 2-(trimethylsilyl)ethyl (1R,2S,5R)-2-((S)-3-benzyloxycarbonylamino-2-oxopyrrolidin-1-yl)-5-(tert-butylamino)cyclohexylcarbamate

Participants

Reaction Steps

To a solution of 2-(trimethylsilyl)ethyl (1R,2S)-2-((S)-3-benzyloxycarbonylamino-2-oxopyrrolidin-1-yl)-5-oxocyclohexylcarbamate (0.550 g, 1.123 mmol) in methylene chloride (0.4 mL) was added t-butylamine (1.180 ml, 11.23 mmol) and Titanium(IV) isopropoxide (6.63 ml, 22.47 mmol). This mixture was stirred for 2 h before sodium cyanoborohydride (127 mg, 2.022 mmol) and MeOH (1 mL) were added. After 2 h, methylene chloride (50 mL) was added, followed by 1N NaOH. The mixture was filtered through Celite to remove the titanium salts. The filtrate was dried and concentrated in vacuo to give 2-(trimethylsilyl)ethyl (1R,2S,5R)-2-((S)-3-benzyloxycarbonylamino-2-oxopyrrolidin-1-yl)-5-(tert-butylamino)cyclohexylcarbamate and its 5S diastereomer as a mixture (510 mg, 0.933 mmol, 83% yield). LC/MS found [M+H]+=547.31.

Provenance & Evidence