Reacción #1244265

Ecuación de reacción

HCl

4-(Azidomethyl)-2,2-dimethyl-1,3-dioxolane

water

TsCl

→

14

Rendimiento 49.0%

3-Azido-2-hydroxypropyl 4-methylbenzenesulfonate

Rendimiento 49.0%

Disolventes

diethyl ether

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Concentraciónconcentrated under reduced pressure
2. 2
   Otroto afford a yellow oil which
3. 3
   Otrowas used for the next step without purification
4. 4
   OtroAfter drying for 0.5 hr
5. 5
   workup.DISSOLUTIONthe residue was dissolved in CH2Cl2 (30 mL)
6. 6
   workup.ADDITIONwas treated with Bu2SnO (0.071 mg, 0.3 mmol)
7. 7
   workup.STIRRINGAfter stirring for 3 hr at room temperature
8. 8
   Otrothe organic layer was separated
9. 9
   ExtracciónThe aqueous layer was extracted with CH2Cl2 (2×50 mL)
10. 10
    Lavadothe organic layer was consecutively washed with H2O (50 mL) and brine (50 mL)
11. 11
    Secadodried over MgSO4
12. 12
    OtroThe solvent was removed under vacuum
13. 13
    Otrothe residue was purified on silica gel using 33% EtOAc/hexanes as the eluent

Procedimiento

4-(Azidomethyl)-2,2-dimethyl-1,3-dioxolane 13 (2.2 g, 13.99 mmol) was dissolved in methanol (25 mL). To this solution was added a solution of HCl in diethyl ether (2M, 5 mL) at 0° C. The mixture was stirred at room temperature overnight, and then concentrated under reduced pressure to afford a yellow oil which was used for the next step without purification. After drying for 0.5 hr, the residue was dissolved in CH2Cl2 (30 mL) and was treated with Bu2SnO (0.071 mg, 0.3 mmol), followed by TsCl (2.86 g, 15.0 mmol) and TEA (2.2 mL, 16 mmol). After stirring for 3 hr at room temperature, water (30 mL) was added and the organic layer was separated. The aqueous layer was extracted with CH2Cl2 (2×50 mL) and the organic layer was consecutively washed with H2O (50 mL) and brine (50 mL) and dried over MgSO4. The solvent was removed under vacuum and the residue was purified on silica gel using 33% EtOAc/hexanes as the eluent to afford 1.86 g of 14 (48% yield) as a clear, colorless oil. 1H NMR (CDCl3, 400 MHz) δ: 7.77 (d, J=8.0 Hz, 2H), 7.34 (d, J=8.0 Hz, 2H), 3.96-4.09 (m, 3H), 3.31-3.40 (m, 2H), 2.43 (s, 3H). Mass Spec (lo-res): Calc'd for C10H13N3O4S: 271.06. found: 294.1 (M+Na+).

Fuente