Reaction #1884980

Reaction equation

N-tert-butoxycarbonyl-3-(4-pentenylthio)-L-valine, methyl ester

lithium hydroxide monohydrate

hydrochloric acid

→

N-tert-butoxycarbonyl-3-(4-pentenylthio)-L-valine

Yield 99.3%

Solvents

diethyl ether

tetrahydrofuran

water

Conditions

Workup

1. 1
   Washwashed with water (3×) and brine
2. 2
   Dryingdried over anhydrous sodium sulfate
3. 3
   Filtrationfiltered
4. 4
   Concentrationconcentrated under vacuum

Procedure

To a solution of 8.52 g (25.7 mmol) of N-tert-butoxycarbonyl-3-(4-pentenylthio)-L-valine, methyl ester in 200 mL of tetrahydrofuran at room temperature was added a solution of 1. Og (26.2 mmol) of lithium hydroxide monohydrate in 50 mL of water. The resulting mixture was stirred at room temperature for 65 hours. To the reaction mixture then was added 28 mL of 1.00N hydrochloric acid. The mixture was diluted with diethyl ether, washed with water (3×) and brine, dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum to afford 8.10 g of N-tert-butoxycarbonyl-3-(4-pentenylthio)-L-valine as a colorless oil. NMR (300 MHz, CDCl3): δ 5.75 (d of d of t, 1 H, J=17.2, 10.3, 6.6 Hz), 5.40 (br s, 1 H), 5.05-4.94 (m, 2 H), 4.28 (br s, 1 H), 2.56 (m, 2 H), 2.13 (quart., 2 H, J=7.3 Hz), 1.63 (quint., 2 H, J=7.3 Hz), 1.44 (s, 9 H), 1.39 (s, 3 H), 1.37 (s, 3 H).

Source