Reaktion #502085

ord-1845d7038c7d4ac7a5d33fed45637898

Reaktionsgleichung

[O]=[Cr](=[O])([O-])[Cl].c1cc[nH+]cc1
pyridinium chlorochromate
O=[Si]([O-])[O-].[Mg+2]
florisil
C=C(C)[C@@H]1CC[C@]2(CO)CC[C@]3(C)[C@H](CC[C@@H]4[C@@]5(C)CC[C@H](O)C(C)(C)[C@@H]5CC[C@]43C)[C@@H]12
betulin
CC(=O)[O-].[Na+]
sodium acetate
→
C=C(C)[C@@H]1CC[C@]2(C=O)CC[C@]3(C)[C@@H](CC[C@@H]4[C@@]5(C)C=CC(=O)C(C)(C)[C@@H]5CC[C@]43C)[C@@H]12
betulone aldehyde
Ausbeute 75.0%

Edukte

[O]=[Cr](=[O])([O-])[Cl].c1cc[nH+]cc1
pyridinium chlorochromate
—
4A
O=[Si]([O-])[O-].[Mg+2]
florisil
C=C(C)[C@@H]1CC[C@]2(CO)CC[C@]3(C)[C@H](CC[C@@H]4[C@@]5(C)CC[C@H](O)C(C)(C)[C@@H]5CC[C@]43C)[C@@H]12
betulin
CC(=O)[O-].[Na+]
sodium acetate

Reagenzien

Keine

Lösungsmittel

ClCCl
CH2Cl2

Reaktionsbedingungen

Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    workup.ADDITIONTo a suspension
  2. 2
    Filtrationfiltered through a short column of silica gel
  3. 3
    SonstigeThe filtrate is evaporated in vacuo

Vorschrift

To a suspension of freshly activated powdered 4A molecular sieves (1.2 g), celite (1.2 g), florisil (1.2 g), sodium acetate (500 mg) and pyridinium chlorochromate (1.2 g) in CH2Cl2 (25 mL) add betulin (500 mg). The mixture is to be stirred for 2 hrs, and then filtered through a short column of silica gel. The filtrate is evaporated in vacuo. The residue is then subjected to column chromatography to afford betulone aldehyde (370 mg) as white solid.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08088757B2uspto-grants-2012_01