Réaction #55054

Équation de réaction

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

KOH

hydrazine hydrate

→

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

Solvants

diethylene glycol

Conditions de réaction

Traitement

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

Mode opératoire

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).

Source