Reaktion #58005

Reaktionsgleichung

alcohol

tert-butyl 4-{2-[(1R)-1-hydroxypropyl]-4,5-dimethylphenyl)-3,6-dihydropyridine-1(2H)-carboxylate

triphenylphosphine

imidazole

→

azide

tert-butyl 4-{2-[(1S)-1-hydroxypropyl]-4,5-dimethylphenyl}-3,6-dihydropyridine-1(2H)-carboxylate

Lösungsmittel

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstige2Py (prepared
2. 2
   workup.ADDITIONAfter the addition
3. 3
   FiltrationThe reaction mixture was filtered through a short column of silica gel
4. 4
   Wascheneluted with the appropriate volume of DCM
5. 5
   Sonstigeto remove excess salts and polar byproducts
6. 6
   EinengenThe filtrate was concentrated in vacuo
7. 7
   Sonstigethe crude residue purified by flash chromatography on silica gel (gradient elution; 0%-20% EtOAc/hexanes as eluent)

Vorschrift

Diisopropylazidocarboxylate (2.96 mL, 15.1 mmol) was added dropwise to a stirred mixture of alcohol 109 (1.3 g, 3.76 mmol), Zn(N3)2.2Py (prepared according to the method described by Viaud, M-C; Rollin, P. in Synthesis, 1990,130), triphenylphosphine (3.95 g, 15.1 mmol) and imidazole (1.03 g, 15.1 mmol) in DCM (100 mL) at approximately 0° C. After the addition, the resulting mixture was allowed to warm to ambient temperature and stirred vigorously for 18 h. The reaction mixture was filtered through a short column of silica gel eluted with the appropriate volume of DCM to remove excess salts and polar byproducts. The filtrate was concentrated in vacuo and the crude residue purified by flash chromatography on silica gel (gradient elution; 0%-20% EtOAc/hexanes as eluent) to afford azide 110 as a colorless oil.

Quelle