Free accessResearch articleFirst published online 1999-9
Boron Trifluoride-assisted Reactions of 1-Benzothiophen-3(2 H )-one with Various Ketones: A Convenient Entry to 2-Methylene-1 -benzothiophen-3(2 H )-one and/or 6 H -Di[1]benzothieno[3,2- b :2,3- e ]pyran Derivatives
The title compounds are obtained in moderate to high yields by BF3-assisted reaction of 1-benzothiophen-3(2H)-one with nine ketones in diethyl ether at room temperature; the relative amounts of pyran 1 and ylidene 2 prove to be dependent upon electronic and steric factors.
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