Di chloromethylene

Thiophene 1,1-dioxide behaves in a different manner it underwent addition of the tri-chloromethyl anion and the product formed eliminated hydrogen chloride giving 3-di-chloromethylene-2,3-dihydrothiophene 1,1-dioxide in 26% yield. 

Di Cesare and Gross175 introduced a procedure using phase-transfer catalysis to induce the action of dichlorocarbene on various protected sugars,176 and obtained the chloro derivative 162c from compound 161. Another, similar migration was observed,178 and confirmed,134,174 for the chlorination of methyl 2,3-anhydro-4,6-0-benzylidene-a-D-al-lopyranoside (166) with (chloromethylene)dimethyliminium chloride, which gave the rearranged chloro derivative 167. 

Condensation of the pyrrolidine enamine of V-[4-(/-butyloxycarbonylphe-nyl)]piperidone and (chloromethylene)malononitrile followed by reaction with ammonia in methanol at room temperature afforded the amino nitrile (IV.234) in 72% overall yield [148]. Cleavage of the t-butyl ester was accomplished readily with HCl in nitromethane, and the resulting acid ((IV.235), 77% yield) was coupled to di-t-butyl L-glutamate with the aid of diphenyl... 

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