Реакция #55054

Уравнение реакции

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

KOH

hydrazine hydrate

→

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

Растворители

diethylene glycol

Условия реакции

Обработка

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

Методика

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).

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