An optically active segment for use in synthesis of a stereocontrolled oligonucleotide represented by the following formula (I), a method for producing the same, and a method for synthesizing a stereocontrolled oligonucleotide therefrom are provided. In formula, B is a protected/unprotected nucleoside base; R.sup.1 is substituted/unsubstituted aliphatic group; R.sup.2, R.sup.3 is a DMTr group or —P(R.sup.11)(NR.sup.12).sub.2; R.sup.11 is OCH.sub.2CH.sub.2CN, SCH.sub.2CH.sub.2CN, etc.; R.sup.12 is a substituted/unsubstituted aliphatic group or aromatic group; X is H, an alkyl, O-alkyl, etc.; Y is H, NHR.sup.13, a halogen, etc., or a hydroxyl group protected with an acyl, ether, or silyl, or forms an X—Y bond with X; and n is an integer of 0 or more and 4 or less.

##STR00001##

A β-modified phosphoric acid compound precursor having a partial structure represented by

##STR00001##

where A.sub.1 represents —SR.sub.1, —S—S—R.sub.1, —SeR.sub.1, or —X, where X is a halogen selected from fluorine, chlorine, bromine, and iodine; R.sub.1 represents hydrogen, an alkyl group having 1 to 20 carbon atoms, or the like; L.sub.1 represents hydrogen, an alkyl group having 1 to 20 carbon atoms, or the like; L.sub.2 represents an alkyl group having 1 to 20 carbon atoms, or the like; L.sub.1 and L.sub.2 may be linked to each other to form a 4 to 6-membered ring structure; L.sub.1 and L.sub.2 may each have a substituent; and the symbol * represents a bond to be bonded to a phosphate group by phosphorylation. Further, provided are a reaction inhibitor and a medicine, each of which includes the β-modified phosphoric acid compound precursor.

A segment for use in synthesis of an oligonucleotide, represented by the following formula (I), a method for producing the same, and a method for synthesizing an oligonucleotide therefrom are provided. In formula (I), B is a protected/unprotected nucleoside base; R.sup.1 is a protecting group; R.sup.2, R.sup.3 and R.sup.4 are OCH.sub.2CH.sub.2CN, OCH.sub.2CH═CH.sub.2, etc.; R.sup.5 is a substituted/unsubstituted aliphatic group/aromatic group; X is a lone pair, O or S; Y is NHR.sup.6, a halogen, CN, etc., or a hydroxyl group protected with an acyl, ether or silyl protecting group; R.sup.6 is H, an aliphatic group or an aromatic group; Z is H, an alkyl, an O- or N-alkyl or a halogen, or forms a Z—Y bond with Y; and (m+n) is an integer of 2 or more and 23 or less.

##STR00001##

The present invention relates to a process for the preparation of Cangrelor in salt form of formula (V) by preparation and subsequent hydrolysis of an intermediate of formula (IV). The process is characterised by the high yield and purity of the product, and can be used industrially.

The present invention relates to chirally controlled oligonucleotides, chirally controlled oligonucleotide compositions, and the method of making and using the same. The invention specifically encompasses the identification of the source of certain problems with prior methodologies for preparing chiral oligonucleotides, including problems that prohibit preparation of fully chirally controlled compositions, particularly compositions comprising a plurality of oligonucleotide types. In some embodiments, the present invention provides chirally controlled oligonucleotide compositions. In some embodiments, the present invention provides methods of making chirally controlled oligonucleotides and chirally controlled oligonucleotide compositions.

The invention provides a process for the preparation of nicotinamide mononucleotide having formula (I): ##STR00001##
The method involves the protection of nicotinamide riboside by ketalization, followed by phosphorylation and then deprotection to provide nicotinamide mononucleotide.

The invention provides a process for the preparation of nicotinamide mononucleotide having formula (I): ##STR00001##
The method involves the protection of nicotinamide riboside by ketalization, followed by phosphorylation and then deprotection to provide nicotinamide mononucleotide.

Described are procedures and intermediates for the preparation of guadecitabine, and guadecitabine salts and solid state forms thereof.

It is provided an achiral, non-nucleosidic backbone for phosphoramidites that can be inserted with high yields in nucleic acid strands and sequence-controlled oligo(phosphodiester)s through solid phase synthesis (SPS) using a DNA synthesizer. From this backbone, platforms with useful chemical handles were synthesized, further functionalized, transformed into phosphoramidites and attached to nucleic acid strands and sequence-controlled oligo(phosphodiester)s. The backbone is based on a tertiary amine with a 3-6 carbon spacer between the central nitrogen and the two external hydroxyls. The spacer has been optimized to increase coupling yields and stability.

Provided are compounds, methods, and pharmaceutical compositions for treating Filoviridae virus infections by administering ribosides, riboside phosphates and prodrugs thereof, of Formula IV:

##STR00001##

The compounds, compositions, and methods provided are particularly useful for the treatment of Marburg virus, Ebola virus and Cueva virus infections.