Diester method

In the diester method a deoxynucleoside-5 -monophosphate is condensed with the 3 -OH group of a deoxynucleotide to produce a 3, 5 -phosphodiester. This is illustrated by a general method for dinucleotide synthesis developed by H.G. Khorana (K.L. Agarwal, 1976). One N-... 

Diester-diamine polyamides, 157-158 Diester-diol enzyme-catalyzed solution reaction, 100-101 Diester-diol reaction, 98 Diester method, 181-182 V,lV-Diethylcyclohexylamine (DECHA), 229... 

Diester methods have been used to synthesize analogues of the initiator codon ApUpG in which the adenine residue has a fixed torsion angle, as for instance in (78),132 and triester methods have been used to prepare dinucleoside phosphates and codon analogues133 134 containing the hydroxyalkyl nucleosides 9-(4 -hydroxybutyl)-adenine (80), 9-(3 -hydroxypropyl)adenine (81), and 1 -(3 -hydroxypropyl)uracil (82), with a view to determining the effect of the achiral residues on the c.d. spectra. 

Fig. 1. DAM synthesis. Principle of the phospho-diester method of DNA synthesis. B = protected base. For other abbreviations and formulas see Fig. 5.

Generally, two different strategies are used in conventional synthesis of oligonucleotides the diester and the triester method [131,132]. In syntheses with soluble polymer supports and in recent works in general the diester method is preferred. Thereby, the 5 -0 position is protected by the solutde polymer and the elongation of the oligonucleotide chain is carried out via the 3 -0 position. Most researchers used an ether, ester, or a carbonate bond for the S -nucleoside linkage. 

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