Synthesis of well-defined phosphate-methylated DNA fragments: the application of potassium carbonate in methanol as deprotecting reagent.
A new deprotection procedure in the synthesis of (partially) phosphate-methylated oligodeoxynucleotides has been developed, involving treatment of fully protected DNA fragments with methanolic potassium carbonate. It is shown that base deprotection can be accomplished in potassium carbonate/methanol without affecting the methyl phosphotriesters. This methodology enables us to synthesize, both in solution and on a solid support, DNA fragments which are phosphate-methylated at defined positions. The solid phase synthesis, however, turns out to be accompanied by considerable demethylation of the phosphotriesters. It is demonstrated that this demethylation does not occur during the deprotection or work-up procedure. Furthermore, it was found that the latter side-reaction is suppressed when the standard capping procedure with acetic anhydride is included.
Kuijpers
W H
WH
Department of Organic Chemistry, Eindhoven University of Technology, The Netherlands.
Huskens
J
J
Koole
L H
LH
van Boeckel
C A
CA
D002254:Carbonates; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol; D008745:Methylation; D015394:Molecular Structure; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis* / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D011188:Potassium
D002254:Carbonates; D009838:Oligodeoxyribonucleotides; D010710:Phosphates; C037593:potassium carbonate; D011188:Potassium; D000432:Methanol