Borane → 5-Hydroxy-2-methylnorvaline

Participants

Reaction Conditions

Reaction Steps

Finely ground racemic a-methylglutamic acid (5.0 g, 0.029 mol) was suspended in THF (30 mL), treated with triethylborane (1M in THF, 32.32 mL, 0.032 mol), and heated at reflux for 36 h. After cooling to 0° C. the soln was treated dropwise with borane in THF (1M, 35.26 mL, 0.035 mol) and stirred at 0° C. for 3 h. The mixture was quenched with 5% aq HCl (30 mL), stirred for 0.5 h, concentrated on a rotary evaporator, and the residue dissolved in 5% HCl (44 mL) and heated at reflux for 0.75 h. After cooling and concentrating, the residue was taken up in MeOH (50 mL), concentrated, and this procedure repeated 3×to give 5.69 g of the title compound which was not purified.

Provenance & Evidence