ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A Novel Example of Reversible Ring Opening: The Epimerization at C(3) of Sugar 3-Hydroxy-Δ1-pyrazolinesReaction of 1 (either geometrical isomer) with hydrazine followed by in situ Ag2O oxidation led to two pairs of interconverting isomers 4 ⇄ 5 and 6 ⇄ 7. By the same treatment, (Z)-10 and (or) (E)-10 gave the pair 11 ⇄ 12. Acetylation of 4 ⇄ 5 led to a non interconverting mixture of 8 and 9. This fact, and the lack of incorporation of 18O when the epimerization took place in the presence of H218O indicated that the most probable mechanism consisted in a reversible ring opening (D ⇄ E ⇄ F). The kinetic parameters of these reactions are given and structural assignments proposed for the new compounds.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19800630205
