Reaktion #55054

Reaktionsgleichung

(2R,6R)-1-hydroxy-2,6,10-trimethylundecan-4-one

KOH

hydrazine hydrate

→

(2R,6R)-(+)-2,6,10-trimethylundecan-1-ol

Lösungsmittel

diethylene glycol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONA mixture of 3.98 g
2. 2
   Temperaturheated until distillation
3. 3
   workup.DISTILLATIONDistillation
4. 4
   Sonstigereached 195° C.
5. 5
   Temperaturat reflux for 4 hours
6. 6
   TemperaturAfter cooling
7. 7
   workup.ADDITIONthe resulting mixture was treated with ice and 3 N aqueous HCl
8. 8
   Extraktionworked-up by ether extraction in the manner of Example 1 giving 2.9 g
9. 9
   SonstigeThis material was chromatographed on 180 g
10. 10
    WaschenElution with 4:1 parts by volume hexane-ether

Vorschrift

A mixture of 3.98 g. (0.0174 mole) of (2R,6R)-1-hydroxy-2,6,10-trimethylundecan-4-one, 108 ml. of diethylene glycol, 25 g. of KOH and 43.5 ml. of hydrazine hydrate was stirred and heated until distillation began. Distillation was then continued until the internal temperature of the reaction mixture reached 195° C. then the mixture was mintained at reflux for 4 hours. After cooling, the resulting mixture was treated with ice and 3 N aqueous HCl and worked-up by ether extraction in the manner of Example 1 giving 2.9 g. of a pale yellow oil. This material was chromatographed on 180 g. of silica gel. Elution with 4:1 parts by volume hexane-ether yielded (2R,6R)-(+)-2,6,10-trimethylundecan-1-ol which was evaporatively distilled affording 2.22 g. of a colorless oil, b.p. 90°-105° C. (bath temperature) (0.2 mm Hg.); [α]25D+ 9.44° (c 2.04, hexane).

Quelle