Réaction #54570

Équation de réaction

chromanone

3-trifluoromethylphenyl magnesium bromide

2-Ethyl-7-hydroxy-2-methyl-4-chromanone

resorcinol

boron trifluoride diethyl etherate

→

chromene

2-Ethyl-4-(3-trifluoromethylphenyl)-7-hydroxy-2-methyl-2H-chromene

Conditions de réaction

Traitement

1. 1
   Autreas described in Preparation 5

Mode opératoire

2-Ethyl-7-hydroxy-2-methyl-4-chromanone, m.p. 109°-110.5° C., was prepared by condensing resorcinol with 3-methyl-2-pentanoic acid in the presence of boron trifluoride diethyl etherate. Reaction of the chromanone with 3-trifluoromethylphenyl magnesium bromide as described in Preparation 5 gave the title chromene as a golden yellow oil.

Source