Reaktion #162044

Reaktionsgleichung

O(Et)2

BF3

D-glucose peracetate

8-pentadecanol

→

glycoside

Ausbeute 100.1%

8-Pentadecanyl 2,3,4,6-tetra-O-acetyl-D-glucopyranoside

Ausbeute 100.1%

Lösungsmittel

DCE

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONbefore pouring onto short plug of silica
2. 2
   Wascheneluting with EtOAc
3. 3
   SonstigeThe solvent was evaporated before the crude material
4. 4
   Sonstigewas purified by column chromatography (SiO2
5. 5
   Waschenloaded with DCM, elution with DCM (100 mL)

Vorschrift

To a solution of D-glucose peracetate (250 mg, 640 μmol) in DCE (1 mL) was added 8-pentadecanol (220 mg, 960 μmol). BF3.O(Et)2 (134 μL, 1.1 mmol) was added and the mixture stirred at room temperature overnight before pouring onto short plug of silica and eluting with EtOAc. The solvent was evaporated before the crude material was purified by column chromatography (SiO2, loaded with DCM, elution with DCM (100 mL), then 20% EtOAc/Hexane to 35% EtOAc/Hexane) to give the glycoside 141 as a white solid (179 mg, 50%). 1H NMR (CDCl3, 400 MHz) δ: 5.19 (dd, 1H, J2,3=9.5, J3,4=0.0, H-3), 5.06 (dd, 1H, J4,5=9.7, H-4), 4.96 (dd, 1H, J1,2=8.0, J2,3=9.6, H-2), 4.52 (d, 1H, H-1), 4.21 (dd, 1H, J5,6b=5.2, J6a,6b=12.1, H-6b), 4.12 (dd, 1H, J5,6a=2.6, H-6a), 3.66 (ddd, 1H, J4,5=10.0, H-5), 3.53 (m, 1H, CH2CHOCH2), 2.07 (s, 3H, OCOCH3), 2.02 (s, 6H, OCOCH3), 2.00 (s, 3H, OCOCH3), 1.60-1.20 (m, ˜24H, CH2), 0.88 (t, 3H, J=7.0, CH3), 0.87 (t, 31-1, J=7.0, CH3).

Quelle