Reaktion #728769

Reaktionsgleichung

HCl

BF3.Et2O

3,4-epoxytetrahydropyran

n-BuLi

1-Methanesulfonyl-4-methylsulfanyl-benzene

→

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

Ausbeute 20.2%

Lösungsmittel

THF

hexane

EtOAc

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 (4.3 g) was dissolved in THF (40 ml) and cooled to −78° C. prior to the slow addition of 1.6 M n-BuLi in hexane (13.4 ml). After 0.5 h, BF3.Et2O (2.7 ml) was added followed by 3,4-epoxytetrahydropyran (2.2 g) (Berti et al. Tetrahedron 1974, 30, 4013) (2.3 g) 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 1N HCl 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