PURPOSE: To obtain advantageously the titled compound useful as an intermediate for medicines and agricultural chemicals in high yield, by using a specific compound having a triarylmethyl group as a catalyst in reaction of silylenol ethers with acetals.
CONSTITUTION: A compound expressed by formula I (R1WR3 and R' represent alkyl, aryl or aralkyl, and R1WR3 further represent H, alkoxyl, aryloxy or aralkyloxy, and preferably those ones having 1W20 carbon atoms; R1 together with R2 or R3 may form a ring) is reacted with a compound expressed by formu la II (R4 and R5 represent same groups as defined for R1WR3; R" represents same groups as defined for R'; X represents O or S) using a compound expressed by formula IV (Ar represents aryl, especially phenyl; Y represents acid residue, especially ClO4, BF4, SbCl6, SO3CF3) as a catalyst to obtain the aimed com pound expressed by formula III in high yield and easily under mild reactor conditions in a short reaction time of about 5min W 5hr, preferably at -80°C W room temperature.
MURAKAMI MASAHIRO
KOBAYASHI OSAMU
