Reaktion #1808710

Reaktionsgleichung

dihydrocholesterol

o-iodoxybenzoic acid

→

5α-cholestan-3-one

Ausbeute 89.5%

Lösungsmittel

THF

DMSO

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAfter 2 hr precipitation of a white solid
2. 2
   workup.ADDITIONAfter 5 hr the reaction solution was poured into Na2CO3 (5%, 40 ml)
3. 3
   Extraktionextracted with diethyl ether/n-hexane (50:50; 3×30 ml)
4. 4
   WaschenThe combined organic layers were washed with water (2×15 ml)
5. 5
   Trocknendried over sodium sulfate
6. 6
   SonstigeThe residue was crystallised from ethanol

Vorschrift

A solution of dihydrocholesterol (1.94 g; 5 mmol) in THF (8 ml) was added to a solution of o-iodoxybenzoic acid I (2.10 g, 7.5 mmol) in DMSO (14 ml). After 2 hr precipitation of a white solid was observed. After 5 hr the reaction solution was poured into Na2CO3 (5%, 40 ml) and extracted with diethyl ether/n-hexane (50:50; 3×30 ml). The combined organic layers were washed with water (2×15 ml), dried over sodium sulfate and brought to dryness under vacuum. The residue was crystallised from ethanol to give 1.73 g (89%) of 5α-cholestan-3-one mp 129°-130° C. (lit. 128°-130° C.: Beilsteins Handbuch der organischen Chemie, III E., 7, 1330b).

Quelle