Reaction between 4-nitrobenzaldoximate ion and phosphotriesters

✍ Scribed by Colin B. Reese; Laval Yau

• Book ID: 104246272
• Publisher: Elsevier Science
• Year: 1978
• Tongue: French
• Weight: 290 KB
• Volume: 19
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)95248-7

✦ Synopsis

A major problem which has arisen in the synthesis of oligonucleotides by the phosphotriester approach has been the significant amount of internucleotide cleavage' accompanying the removal-of otherwise satisfactory aryl protecting groups. Thus treatment of a phenylprotected dinucleoside phosphate (represented by la) with hydroxide ion (Scheme 1; X=H) leads*, even under the most favourable conditions so far found, to 97-98% of the desired product (represented by 3) and ea. Z-3% of internucleotide cleavage products (represented by 4). This clearly becomes a serious problem in the unblocking of protected oligonucleotides containing a comparatively large number (say, 15 or more) residues'.

Scheme 1

RIO, 40

x0;