Reaktion #730089

Reaktionsgleichung

tetramethylguanidine

lithium chloride

4-benzyloxy-3,5-dimethylbenzaldehyde

diethyl (3-oxo-1,4-dioxaspiro[4.5]dec-2-yl)-phosphonate

Diethyl(3-oxo-1,4-dioxaspiro[4.5]dec-2-yl)-phosphonate

→

(3E)-3-[[3,5-dimethyl-4-(phenylmethoxy)phenyl]methylene]-1,4-dioxaspiro[4.5]decan-2-one

Lösungsmittel

tert.butyl-methylether

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Sonstigeformed
3. 3
   Temperaturis heated to ambient temperature
4. 4
   Waschenis washed with 150 mL water and 30 mL saturated saline solution
5. 5
   Sonstigedried
6. 6
   Sonstigeevaporated down
7. 7
   workup.STIRRINGstirred intensively for 1 hour at −10° C., during which time a white solid
8. 8
   Sonstigeis formed
9. 9
   SonstigeThe solid formed
10. 10
    Filtrationfiltered
11. 11
    Waschenwashed twice with 20 mL methanol/water (1:1)
12. 12
    Sonstigedried at 45° C

Vorschrift

4.2 g lithium chloride (0.1 Mol), 20.0 g (83.2 mmol) of 4-benzyloxy-3,5-dimethylbenzaldehyde (D) and 31.62 g (108.2 mmol) of diethyl (3-oxo-1,4-dioxaspiro[4.5]dec-2-yl)-phosphonate (C) are suspended in 130 mL tetrahydrofuran and cooled to −20° C. At this temperature 12.5 mL (0.1 Mol) tetramethylguanidine are added dropwise. After the addition has ended the suspension formed is heated to ambient temperature and stirred for 1 hour. After the addition of 190 mL tert.butyl-methylether the organic phase is washed with 150 mL water and 30 mL saturated saline solution, dried and evaporated down. The resulting yellow oil is taken up in 145 mL methanol and stirred intensively for 1 hour at −10° C., during which time a white solid is formed. The solid formed is suction filtered, washed twice with 20 mL methanol/water (1:1) and dried at 45° C. Yield: 26.0 g (86% of theory)

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