Reacción #7771

Ecuación de reacción

NH4Cl

BF3 Et2O

(±)(1S*,2R*,4S*)-4-(benzyloxy)-1,2-epoxycyclohexane

1-Methanesulfonyl-4-methylsulfanyl-benzene

nBuLi

→

(±)(1R*,2R*,5S*)-5-benzyloxy-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexanol

Rendimiento 80.3%

Disolventes

THF

EtOAc

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONAfter an addition 1 h at −78° C.
2. 2
   Temperaturathe solution was warmed to 0° C
3. 3
   workup.WAITAfter 2 h
4. 4
   Temperaturathe solution was cooled to −78° C.
5. 5
   TemperaturaThe solution was warmed to rt
6. 6
   LavadoThe organic layer was washed with brine
7. 7
   Otrodried
8. 8
   Filtraciónfiltered
9. 9
   Concentraciónconcentrated

Procedimiento

1-Methanesulfonyl-4-methylsulfanyl-benzene (3.25 g) was dissolved in THF (50 mL) and cooled to −78° C. prior to the addition of 1.6 M nBuLi (10 mL). After 0.5 h, BF3-Et2O (2.04 mL) was added followed by (±)(1S*,2R*,4S*)-4-(benzyloxy)-1,2-epoxycyclohexane (2.19 g) (Chini et al. J. Org. Chem. 1990, 55, 4265) in THF (20 mL). After an addition 1 h at −78° C., the solution was warmed to 0° C. After 2 h, the solution was cooled to −78° C. and saturated NH4Cl solution (aq) was added. The solution was warmed to rt and EtOAc was added. The organic layer was washed with brine, dried, filtered, and concentrated. Flash chromatography of the resulting residue gave (±)(1R*,2R*,5S*)-5-benzyloxy-2-(4-methylsulfanyl-benzenesulfonylmethyl)-cyclohexanol (3.5 g) as the major product: 1H NMR (CDCl3, δ ppm, 300 mHz) 1.41 (m, 2H), 1.59 (m, 1H), 1.95 (m, 1H), 2.05-2.35 (m, 2H), 2.54 (s, 3H), 2.96 (dd, 1H), 3.64 (m, 2H), 3.81 (s, 1H), 4.48 (m, 2H), 7.3 (m, 7H), 7.82 (d, 2H)

Fuente