Tetrahydrofuran → tert-Butyl hydrogen (1,5-dihydroxypentan-2-yl)carbonimidate

Participants

Reaction Conditions

Reaction Steps

A 20 L reactor was charged with 10 L of dry THF and LiBH4 (400 g) and cooled to 0° C. A THF solution of (S)-dimethyl 2-(tert-butoxycarbonylamino)pentanedioate (1000 g/3.63 mol, dissolved in 2 L of dry THF) was then added dropwise while keeping the internal temp. below 15° C. The mixture was slowly warmed to room temperature and stirred for 16 h. Cooled to 0° C., then MeOH (10 L) was added dropwise to the reaction mixture to quench the excess amount of reducing reagent. Concentrated, and the residue was poured into 5 L water. After extraction with ethyl acetate, the combined organic phase was dried over Na2SO4. After filtration the solvent was removed in vacuo to give 730 g of crude (S)-tert-butyl 1,5-dihydroxypentan-2-ylcarbamate as a pale yellow oil.

Provenance & Evidence