Nucleic Acids Research, 1990, Vol. 18, No. 17 5083-5088
© 1990
CHEMISTRY |
Diastereomeric dinucleoside-methylphosphonates: determination of configuration with the 2-D NMR ROESY technique
Institut für Organische Chemie, Niederurseler Hang D-6000 Frankfurt am Main 50, FRG
Received June 11, 1990. Revised August 1, 1990. Accepted August 1, 1990.
The determination of configuration at phosphorus in diastereomeric dinucleoside-methylphosphonates having the -O-P(=O)(-CH3)-O- Internucleotide linkage with the NOE derived ROESY NMR technique is described for ApT, TpT, ApA, TpA and CpG. For this purpose ROE's from the P-CH3 group to the protons in the nearest neighbourhood were measured. These ROE's are different within diastereomeric pairs of a dimer enabling us to deduce the individual configuration. The validity of the method is proven in comparison with dimers of known configuration (ApT, TpT). Together with a recently published diastereoselective synthesis method a more homogeneous picture between physical properties and the corresponding configuration is provided. There is an improvement in our knowledge about the stereochemistry of these substances which could not be deduced from the data known before.