Cycloaddn. of ClFC.bul. to olefins RR1C:CHR2 (R = alkyl or substituted alkyl, e.g., Et, ClCH2, AcOCH2CH2CH2; R1 = H, Me, Et; R2 = H, Me) gave 1-chloro-1-fluorocyclopropanes; these were acetolyzed to RR1C:CFCHR2OAc, which were hydrolyzed to RR1C:CFCHR2OH. The convenience and efficiency of the cycloaddn. reaction, which takes place in a 2-phase system even in the presence of base-sensitive substituents, makes the process attractive for prepg. 2-fluoroallylic alcs. [on SciFinder (R)]