Nucleophilic fluorination by selective ring opening of α-halooxiranes

Reaction of 1,3,3-trihalo-7-oxabicyclo[4.1.0]heptanes with boron trifluoride–ether or HF· pyridine resulted in the regio-and stereo-selective formation in high yield of the corresponding cis-fluorohydrins; using a succession of cyclisations followed by ring-opening reactions by fluoride afforded an iterative preparation of unknown 2,2,6,6-tetrafluorocyclohexanol 13 starting from the chlorinated analogue 1.