Diflorodiiodomethane (CF2I2, 1) can react with vinyl ethyl ether by Na2S2O4 in a solvent [V(EtOH): V(DMSO)=10:1] at room temperature for 8 hours to give diethyl 3,3-difluoro-3-iodopropylacetal [ [ICF2CH2CH (OEt)2](3). in 60% vyeld. The cou;oing of 3 with zinc in DMF affords [ (EtO)2CHCH2CF2CF2CH2CH(OEt)2](5) in 60% yield. The SnCl4-promoted cross-coupling reaction of the acetals 3 and 5 with trimethylsilyl enol ethers produce ketones ICF2CH2CH(OEt)CH2COR (8) and RCOCH2CH (OEt)CH2CF2CF2CH2CH(OEt)CH2COR(9) respectively. 3 can add to trimethylsilyl enol ethers initiated by Zn or sodium dithionite to yield (EtO)2CHCH2CF2CH2CH (OTMS) C6H5 (10c) or (EtO)CHCH2CF2CH2COC (CH3)3(11a). The acetals 3 and 5 can be converted by BF3·Et2O into the corresponding dithioacetals ICF2CH2CH(SR)2(13), (RS) 2CHCH2CF2CF2CH2CH(SR)2(14) or O,S- acetal EtOCH(SR)CH2CF2CF2CH2CH(SR) (OEt)(15) depending upon the concentration of RSH used. The elimination of HI from 13 by ENt3 results in the formation of 1,1- difluoroethylene derivatives.

Key words: ACETAL, MERCAPTAL, SODIUM THIOSULFATE, DIMETHYLSULFOXIDE