Synthesis of Oligodeoxyribo‐ and Oligoribonucleotides According to the H‐Phosphonate Method

Oligonucleotides can be synthesized by condensing a protected nucleoside H‐phosphonate monoester with a second nucleoside in the presence of a coupling agent to produce a dinucleoside H‐phosphonate diester. This can then be converted to a dinucleoside phosphate or to a backbone‐modified analog such as a phosphorothioate or phosphoramidite. This unit discusses four alternative methods for synthesizing nucleoside H‐phosphonate monoesters. The methods are efficient and experimentally simple, and use readily available reagents. The unit describes the activation of the monoesters, as well as competing acylation and other potential side reactions.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143594/1/cpnc0304.pd

Deoxyribo‐ and Ribonucleoside H‐Phosphonates

Most methods for preparing H‐phosphonate monoesters suffer from variable yields and are often incompatible with common protecting groups used in oligonucleotide synthesis. This unit describes four procedures that consistently give high yields of the desired products. Taken together, they provide an arsenal of phosphonylation prodecures that it compatible with most common protecting groups.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143703/1/cpnc0206.pd

Synthetic Strategies and Parameters Involved in the Synthesis of Oligodeoxyribo‐ and Oligoribonucleotides According to the H

Oligonucleotides can be synthesized by condensing a protected nucleoside H‐phosphonate monoester with a second nucleoside in the presence of a coupling agent to produce a dinucleoside H‐phosphonate diester. This can then be converted to a dinucleoside phosphate or to a backbone‐modified analog such as a phosphorothioate or phosphoramidite. This unit discusses four alternative methods for synthesizing nucleoside H‐phosphonate monoesters. The methods are efficient and experimentally simple, and use readily available reagents. The unit describes the activation of the monoesters, as well as competing acylation and other potential side reactions.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143625/1/cpnc0304.pd

A 500-MHz proton-magnetic-resonance study of several fragments of the carbohydrate-protein linkage region commonly occurring in proteoglycans

The proton-magnetic-resonance spectra of three partial structures of the carbohydrate-protein linkage region that frequently occurs in proteoglycans, namely, beta-d-Galp-(1->3)-beta-d-Galp-(1->4)-beta-d-Xylp-(1->O)-l-Ser, were recorded in 2H2O at 500 MHz; they could be completely interpreted, both for the glyco-serines and for the corresponding glyco-xylitols. The chemical shifts and the coupling constants were refined by computer simulation of the spectra. The change in the chemical shift of H-4 of a d-galactopyranosyl residue upon substitution at C-3 by a beta-d-galactopyranosyl group is proposed to be characteristic for this particular attachment, making H-4 of galactose a structural-reporter group. The three constituting monosaccharides adopt the 4C1 (d) ring conformation. The terminal galactopyranosyl group and the internal galactopyranosyl residue differ as to the population of rotamers around the C-5/C-6 axis. Concomitantly, the flexibility of their glycosidic linkages is distinct