Reacción #2200587

Ecuación de reacción

(S)-(−)-1-phenylethylamine

(2S,3S)-2-methyl-3-tetrahydropyranyloxybutyraldehyde

(2S,3S)-2-methyl-3-benzyloxybutyraldehyde

methanol

TMSCN

→

(1R,2R,3S)-1-cyano-2-methyl-3-tetrahydropyranyloxy-N-[(S)-1′-phenylethyl]butylamine

(1S,2R,3S)-1-cyano-2-methyl-3-tetrahydropyranyloxy-N-[(S)-1′-phenylethyl]butylamine

Rendimiento 90.0%

Disolventes

dichloromethane

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITat room temperature for 22 hours
2. 2
   Otrothe reaction mixture was separated in saturated NaHCO3
3. 3
   ExtracciónThe aqueous phase was extracted with ether
4. 4
   Lavadothe ether extracts were washed with brine, they
5. 5
   Otrowere dried
6. 6
   Filtraciónfiltered on a short disk of Celite and Na2SO4

Procedimiento

(S)-(−)-1-phenylethylamine (211 mg, 225 μl, 1.74 mmol) was added at room temperature to a solution of (2S,3S)-2-methyl-3-tetrahydropyranyloxybutyraldehyde (6) (270 mg, 1.45 mmol) in dichloromethane (6 ml), and the stirring was continued at room temperature for 2 hours. The reaction mixture was cooled to 0° C., and methanol (2 ml) and TMSCN (216 mg, 290 μl, 2.18 mmol) were successively introduced. After stirring at 0° C. for 2 hours and then at room temperature for 22 hours, the reaction mixture was separated in saturated NaHCO3 and ether. The aqueous phase was extracted with ether, the ether extracts were washed with brine, they were dried and filtered on a short disk of Celite and Na2SO4 and then evaported. Flash chromatography on a silica gel column with, as eluent, a heptane/EtOAc=10:1 then 8:1 mixture produced (1R,2R,3S)-1-cyano-2-methyl-3-tetrahydropyranyloxy-N-[(S)-1′-phenylethyl]butylamine (1R)-(17) and (1S,2R,3S)-1-cyano-2-methyl-3-tetrahydropyranyloxy-N-[(S)-1′-phenylethyl]butylamine (1S)-(17) (414 mg in total, 90%) in the ratio of about 1:3.

Fuente