Reaction #710554

Reaction equation

tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-3-fluoroallylcarbamate

TBAF

→

(E)-tert-butyl 3-fluoro-2-(hydroxymethyl)allylcarbamate

Yield 15.6%

(Z)-tert-butyl 3-fluoro-2-(hydroxymethyl)-allylcarbamate

Yield 6.5%

Solvents

THF

Conditions

Workup

1. 1
   workup.WAITThe resulting solution was left
2. 2
   OtherThe reaction mixture was partitioned between water (70 mL) and ethyl acetate (50 mL)
3. 3
   ExtractionThe aqueous layer was extracted with ethyl acetate (50 mL)
4. 4
   Washthe combined organics were washed with saturated aqueous NH4Cl (70 mL)
5. 5
   DryingAfter drying over Na2SO4
6. 6
   Concentrationthe organics were concentrated in vacuo
7. 7
   OtherPurification of the crude material over silica gel eluting with 20% ethyl acetate and 5% THF in n-hexane

Procedure

To a stirring solution of tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-3-fluoroallylcarbamate (E/Z=1:1; 12.0 g, 37.6 mmol) in THF (30 mL) at room temperature was added TBAF (1:0 M in THF; 45.1 mL, 45.1 mmol). The resulting solution was left to stir for 30 min. The reaction mixture was partitioned between water (70 mL) and ethyl acetate (50 mL). The aqueous layer was extracted with ethyl acetate (50 mL) and the combined organics were washed with saturated aqueous NH4Cl (70 mL) followed by brine (70 mL). After drying over Na2SO4, the organics were concentrated in vacuo. Purification of the crude material over silica gel eluting with 20% ethyl acetate and 5% THF in n-hexane gave (Z)-tert-butyl 3-fluoro-2-(hydroxymethyl)-allylcarbamate (0.5 g, 6.5%), (E)-tert-butyl 3-fluoro-2-(hydroxymethyl)allylcarbamate (1.2 g, 15.6%) and a mixture of the E/Z isomers (5.5 g, 71.4%).

Source