NMR of Terminal Oxygen. Part 14 . Kinetically stabilized simple enols containing methylated uracil groups: Application of a  17 O‐NMR test of H‐bonding | Zendy

Zhuo JinCong | Zendy; Wyler Hugo | Zendy; Péchy Peter | Zendy; Dahn Hans | Zendy

Premium

NMR of Terminal Oxygen. Part 14 . Kinetically stabilized simple enols containing methylated uracil groups: Application of a 17 O‐NMR test of H‐bonding

Author(s) -

Zhuo JinCong,

Wyler Hugo,

Péchy Peter,

Dahn Hans

Publication year - 1994

Publication title -

helvetica chimica acta

Language(s) - English

Resource type - Journals

SCImago Journal Rank - 0.74

H-Index - 82

eISSN - 1522-2675

pISSN - 0018-019X

DOI - 10.1002/hlca.19940770131

Subject(s) - chemistry , steric effects , enol , proton nmr , ring (chemistry) , nmr spectra database , crystallography , double bond , solvent , uracil , stereochemistry , nuclear magnetic resonance spectroscopy , spectral line , polymer chemistry , organic chemistry , catalysis , physics , astronomy , dna , biochemistry

In the crystalline N,N′ ‐dimethylated uracil derivatives 2a , b , the kinetically stabilized enol group forms an H‐bond with OC(4), as demonstrated by increased shielding of specifically labelled 2a and 2b in the 17 O‐NMR spectra (Δδ( 17 O)(C(4)—O) −30 ppm); absence of dilution and solvent effects show that the H‐bridge is intra‐molecular, forming an eight‐membered chelate ring. The (apparent) shielding effect Δδ( 17 O) in 2a, b is larger than that in salicylamide. The strong H‐bond explains why the enols 2 , in spite of the absence of steric hindrance, are kinetically stabilized.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here

Accelerating Research