Dichlorodiphenylsilane → Octaphenylcyclotetrasiloxane

Reaktionsgleichung

[C:1]1([Si:7]([C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)(Cl)Cl)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[OH-:16].[K+]>CC(C)=O.O>[C:1]1([Si:7]2([C:10]3[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=3)[O:16][Si:7]([C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][CH:15]=3)([C:1]3[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=3)[O:16][Si:7]([C:10]3[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=3)([C:1]3[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=3)[O:16][Si:7]([C:10]3[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=3)([C:1]3[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=3)[O:16]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Komponenten

Versuchsvorschrift

A mixture of 510 g of diphenyldichlorosilane in 500 ml of acetone was added dropwise in the course of 3 hours to a hot solution, at 60° C, of 340 g of KOH in 1 l of water, while stirring vigorously. The acetone and a little water were then distilled off and, after cooling the residue, the crystalline octaphenylcyclotetrasiloxane was filtered off and washed with water. After drying, 376 g (94% yield) of octaphenylcyclotetrasiloxane of melting point 187° C (metastable crystal modification) were obtained. After recrystallization from toluene, the product had a melting point of 201° C.