Unusual rearrangement of β-chloro(bromo)-containing 2,3-epoxy-polyfluorobutanes in the reaction with antimony pentafluoride

PS

255

UNUSUAL REARRANGEMENT OF O_CHLOROCBROMO)-CONTAINING 23-EPOXYPOLYFLUOROBUTANES IN THE REACTION WITH ANTIMONY PENTAFLUORIDE

A.Ya.Zapevalov,

T.I.Filyakova.

E.G.Matochklna

and

M.I. Koders

Department of Fine Organic Synthesis of Ural Division of USSR Acad. Sci., S.Kovalevskoj Str. 20, Sverdlovsk (U.S.S.R.)

Oxides of chloro- and bromo-containing polyfluoro-2-butenes Cl-31 have been prepared by an epoxidation

of

corresponding

olefines

with aqueous sodium hypochlorite in the presence of acetonitrile. The interaction of oxides Cl-33

with SbF,

study.

The

ring-

opening of oxirane function by antimony pentafluoride

was

was

first

found to accompany the migration of chlorine or bromine atom. Cl CF,CF--cFCF,

CF,COCFCI CF,

+

+

Cl>

CF&OCF,CF, C!B

c4>

v

CF,COCF,CF,CI C6) [43:[53:[6]

SbF,

Cl CF,CF--CFCF,Cl v c2>

I-L-

150%

CF,CFCI

COCF,CI (71

+ Cl CF,CF,COCF,CI (8) [7]:[4]:[8]:[6]

BrCF,CF--CFCF, v

= 60:30:10 + CF,CFCI

COCF, c4>

+ Cl CFICFpCOCF, Cf3> = 63:18:12:7

CF&OCFBrCF, CQI

(31

The formation of products C4, 7, 91 from reaction (X-oxides Cl-3 with SbF, can be explained by rearrangement of the cationic intermediates.