Lithium Hydroxide → (2E)-5-tert-Butoxycarbonylamino-3,5-dimethylhex-2-enoic acid

Participants

Reaction Steps

(E)-5-tert-Butoxycarbonylamino-3,5-dimethylhex-2-enoic acid ethyl ester (1.95 g; 6.83 mmol) was dissolved in 1,4-dioxane (25 ml) and water (15 ml). Lithium hydroxide (0.18 g; 7.52 mmol) was added and the reaction mixture was stirred for 12 h at room temperature. Water (150 ml) and tert-butyl methyl ether (150 ml) was added. The aqueous phase was diluted with an aqueous solution of sodium hydrogensulfate (10%) until pH 2.5 and extracted with tert-butyl methyl ether (3×100 ml). The combined organic phases were dried over magnesium sulfate and evaporated in vacuo. The residue was recrystallized from heptane (20 ml) to afford 0.6 g of (2E)-5-tert-butoxycarbonylamino-3,5-dimethylhex-2-enoic acid.

Provenance & Evidence