Reaktion #590114

Reaktionsgleichung

NH4Cl

BF3

(±)3,4-epoxytetrahydropyran

1-Methanesulfonyl-4-methylsulfanyl-benzene

nBuLi

→

(±) (3S*,4R*)-4-(4-methylsulfanyl-benzenesulfonylmethyl)-tetrahydro-pyran-3-ol

Ausbeute 35.9%

Lösungsmittel

EtOAc

Et2O

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter an addition 1 h at −78° C.
2. 2
   Temperaturthe solution was warmed to 0° C
3. 3
   workup.WAITAfter 2 h
4. 4
   Temperaturthe solution was cooled to −78° C.
5. 5
   TemperaturThe solution was warmed to rt
6. 6
   WaschenThe organic layer was washed with brine
7. 7
   Sonstigedried
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated

Vorschrift

1-Methanesulfonyl-4-methylsulfanyl-benzene (4.33 g) was dissolved in THF (50 mL) and cooled to −78° C. prior to the addition of 1.6 M nBuLi (13.4 mL). After 0.5 h, BF3. Et2O (2.7 mL) was added followed (±)3,4-epoxytetrahydropyran (1.2 g) (Tetrahedron 1974, 4013). 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 (±) (3S*,4R*)-4-(4-methylsulfanyl-benzenesulfonylmethyl)-tetrahydro-pyran-3-ol (1.3 g) as the major product. MS found: (M+H)+=303.0.

Quelle