[diablo]

Hello,

does anyone of you know or even have experience with how to cleave a urethane bond?

Would really appreciate any *delete me*

[discodermolide]

I've used conc. HCl at reflux or conc. NaOH at reflux.

[diablo]

Thanks, I forgot to mention that the urethane bond is a part of a construction, that is linked to a peptide.

I just want to crack open the urethane bond without harming the peptide - I assume that under conc.HCl my peptide will hydrolyse, am I right?

[TwistedConf]

What's the structure?   That will affect the answer.  Obviously something like a Boc group can be removed easily without affecting a peptide bond, but that's based on having the t-butyl.

[discodermolide]

Thanks, I forgot to mention that the urethane bond is a part of a construction, that is linked to a peptide.

I just want to crack open the urethane bond without harming the peptide - I assume that under conc.HCl my peptide will hydrolyse, am I right?

Well had you made the question somewhat more specific then my answer would have not been that which I gave.

[Arkcon]

Thanks, I forgot to mention that the urethane bond is a part of a construction, that is linked to a peptide.

I just want to crack open the urethane bond without harming the peptide - I assume that under conc.HCl my peptide will hydrolyse, am I right?

Do you mean, its part of a building, and you want to cleave the bond specifically in place?  You're kinda asking on the wrong forum.  If you browse this Organic Chemistry sub-forum of the Chemical forums, you'll find that most of the organic chemistry answers do expect you to conduct the reactions inside ground glassware, in a lab, in a hood, at a university or industrial laboratory, with access to reagents that might need special permissions to purchase, and special safety precaution to use.  Maybe you want to be really way more specific about the "peptide" in question. 

[camptzak]

I am interested in seeing the structure. isnt the carbamate more acid sensitive than an amide? so you could cleave the carbamate without disturbing the amide with the correct pH?

[diablo]

Thanks for all of your comments

Here's the picture (hope it works)

http://picturepush.com/public/13336482

[orgopete]

This question is a little different than one about peptide chemistry. In peptide chemistry, the carbamate protecting group are designed for easier removal with unwanted cleavage or racemization reactions taking place. In this case, I suggest the use of acid or base can selectively remove the blocking groups, but with varying degrees of selectivity or other side reactions.