Reaction #1884984

Reaction equation

isopropyl 5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoate

lithium hydroxide hydrate

→

5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoic acid

Solvents

THF water

water

Conditions

Workup

1. 1
   Washwashed with ether, pH of aqueous fraction
2. 2
   Extractionextracted with ether
3. 3
   Washwashed with saturated NaCl
4. 4
   Dryingdried (MgSO4)
5. 5
   Otherevaporated

Procedure

A mixture of isopropyl 5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoate (product of step 26D, 16.1 g, 51.1 mmol) and lithium hydroxide hydrate (4.19 g, 102 mmol) in THF/water (100 mL/20 mL) was stirred at room temperature under nitrogen for 16 hours. The reaction was diluted with water, washed with ether, pH of aqueous fraction adjusted to ˜4, extracted with ether, combined organic fractions washed with saturated NaCl, dried (MgSO4) and evaporated giving 5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoic acid as a light yellow syrup: 1H NMR (300 MHz, Chloroform-D) δ 5.89 (ddt, 1 H, J=17.4, 10.4, 5.5), 5.25 (dd, 1 H, J=17.4, 1.6 Hz), 5.17 (dd, 1 H, J=10.4, 1.6 Hz), 4.30 (br d, 1 H, J=6.2), 3.96 (dt, 2 H, J=5.9, 1.5 Hz), 3.46 (t, 2 H, J=5.9 Hz), 1.96-1.86 (m, 1 H), 1.85-1.77 (m, 1 H), 1.75-1.64 (m, 2 H), 1.43 (s, 9 H). LCMS m/z 274 (M+H)+.

Source