Acyl group migration and cleavage in selectively protected beta-d-galactopyranosides as studied by NMR spectroscopy and kinetic calculations.
The migration of acetyl, pivaloyl, and benzoyl protective groups and their relative stabilities at variable pH for a series of beta- d-galactopyranoses were studied by NMR spectroscopy. The clockwise and counterclockwise migration rates for the different ester groups were accurately determined by use of a kinetic model. The results presented provide new insights into the acid and base stabilities of commonly used ester protecting groups and the phenomenon of acyl group migration and may prove useful in the planning of synthesis strategies.
Roslund
Mattias U
MU
Laboratory of Organic Chemistry and Laboratory of Industrial Chemistry, Abo Akademi University, FI-20500 Abo, Finland. mattias_roslund@yahoo.com
Aitio
Olli
O
Wärnå
Johan
J
Maaheimo
Hannu
H
Murzin
Dmitry Yu
DY
Leino
Reko
R
D005690:Galactose / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation
D005960:Glucosides; D005690:Galactose