Reaktion #2450

Reaktionsgleichung

water

9-hydroxymethyl-7, 12-dioxaspiro[5,6]dodecane

p-toluenesulphonic acid

→

9-(2-hydroxyethyl)-7, 11-dioxaspiro[5,5]undecane

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe benzene layer was separated
2. 2
   Extraktionthe aqueous layer extracted with benzene
3. 3
   TrocknenThe combined benzene solution was dried over K2CO3
4. 4
   Sonstigeevaporate to a residue (4 g)

Vorschrift

A solution of 9-hydroxymethyl-7, 12-dioxaspiro[5,6]dodecane of the formula V (4 g) of the drawings in benzene (15 ml) was stirred at 10° C. for 5 hr with anhydrous p-toluenesulphonic acid (0.2 g). The reaction mixture was made alkaline by adding TEA and water. The benzene layer was separated and the aqueous layer extracted with benzene. The combined benzene solution was dried over K2CO3 and evaporate to a residue (4 g). It was chromatograped on silicagel using chloroform-methanol mixture as eluent to give 9-(2-hydroxyethyl)-7, 11-dioxaspiro[5,5]undecane of formula VI (2.8 g) (70%) of the drawings as colorless viscous liquid.

Quelle