[nilgnay2]

Hello everyone:
   I want you can give me a help for the synthesis of cyclobutyl bromide.
The below is needed:
   The first reagent must be cyclopropylcarbinol.
Could you suggest me a road to synthesize this compound? I'll appreciate for your help.Thank you!

[GSR]

hi,

here is some procedure


                          hot alkaline KMno4/or  CrO3 in H2SO4     HgO, Br2,heat
cyclopropylcarbinol   ----------->  cyclobutanecarboxylic aid       ------------>        cyclobutyl bromide
                                                                                  ccl4, dark

you can get the procedure for the conversion of acid to halide from Organic Syntheses, Coll. Vol. 6, p.179 (1988); Vol. 51, p.106 (1971)
which is available free by searching from http://www.orgsyn.org/( MERCURY(II) OXIDE-MODIFIED HUNSDIECKER REACTION: 1-BROMO-3-CHLOROCYCLOBUTANE.

hope this will help you.

cheers

GSR

[HP]

Well, HgO is pretty nasty reagent to work up with and also  Hunsdiecker and Borodin many years before has done this reaction with Ag-salt carboxylic acid and Br2...

[movies]

                          hot alkaline KMno4/or  CrO3 in H2SO4     HgO, Br2,heat
cyclopropylcarbinol   ----------->  cyclobutanecarboxylic aid       ------------>        cyclobutyl bromide
                                                                                  ccl4, dark

Are you sure that's correct?  Seems to me you added a carbon in the first step.

I think that you can convert cyclopropyl carbinol to cyclobutyl bromide by just treating the alcohol with PBr₃ or POBr₃.  First making the cyclopropylcarbinyl cation which can rearrange to cyclobutyl cation which could be trapped with Br-.

[wereworm73]

You don't need to bother with the permaganate.  Just heat the cyclopropylcarbinol in 2M HCl at 100^oC and then treat the resulting cyclobutanol with PBr₃ to convert it to a bromide. 

Movies' idea could be a nice shortcut, though.  You might want to test a little bit of cyclopropylcarbinol with PBr₃ and see if you get a good yield of bromocyclobutane.   

[nilgnay2]

       .
I think that you can convert cyclopropyl carbinol to cyclobutyl bromide by just treating the alcohol with PBr₃ or POBr₃.  First making the cyclopropylcarbinyl cation which can rearrange to cyclobutyl cation which could be trapped with Br-.

Oh,thank you for your advice, I think it is a good road to convert cyclopropylcarbinyl to cyclobutylbromide.
And, your mechanism is correct.
I'll have a try by the method that your adviced, and the method adviced by wereworm73
thank you !