This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: less strerically congested. (Any plausible reasoning along those lines will do…) 4. Why is hydrochloric acid added at the end of the reaction with sodium borohydride? Why do bubbles appear in the solution? ( 2 points ) The aqueous hydrochloric acid solution is added to cause the hydrolysis of the borate ester to the alcohol and boric acid. It also quenches any unreacted sodium borohydride, producing hydrogen gas. 4. Give the mechanism of the hydrolysis of the B(OR) 4- intermediate, producing boric acid B(OH) 3 . ( 4 points ) OR B RO OR OR OR B RO OR OR H-HOR B RO OR OR H 2 O OH B RO OR OR H ± H OR B RO OR OH H etc. H OH 2-HOR-H 2 O The complete mecanism does not have to be shown. As long as the part shown here is there, with the detailed dissociation of the first OR, followed by association of the first water molecule to get back to a tetravalent boron species. The charges and their positions are important....
View Full Document
This note was uploaded on 01/13/2010 for the course CHM chm2526 taught by Professor Louise during the Spring '09 term at University of Ottawa.
- Spring '09