Provided is a polymerizable compound represented by a Formula E-1 or Formula E-2 shown in the description. In Formula E-1 or Formula E-2, R.sup.1 represents an alkoxy group, —NR.sup.N.sub.2, a hydroxy group, an aryl group, or an alkyl group, wherein R.sup.N each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; n represents an integer from 1 to 5; R.sup.3 represents a hydrogen atom, an acetyl group, a phenoxyacetyl group, a pivaloyl group, a benzyl group, a 4-methoxybenzyl group, a benzoyl group, a triphenylmethyl group, a 4,4′-dimethoxytrityl (DMTr) group, a 4-methoxytrityl (MMTr) group, a 9-phenylxanthenyl group, a trimethylsilyl group, a cyanomethoxymethyl group, a 2-(cyanoethoxy)ethyl group, or a cyanoethoxymethyl group; and X represents a structure represented by any one of Formula B-1 to Formula B-5 shown in the description.

Provided is a polymerizable compound represented by a Formula E-1 or Formula E-2 shown in the description. In Formula E-1 or Formula E-2, R.sup.1 represents an alkoxy group, —NR.sup.N.sub.2, a hydroxy group, an aryl group, or an alkyl group, wherein R.sup.N each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; n represents an integer from 1 to 5; R.sup.3 represents a hydrogen atom, an acetyl group, a phenoxyacetyl group, a pivaloyl group, a benzyl group, a 4-methoxybenzyl group, a benzoyl group, a triphenylmethyl group, a 4,4′-dimethoxytrityl (DMTr) group, a 4-methoxytrityl (MMTr) group, a 9-phenylxanthenyl group, a trimethylsilyl group, a cyanomethoxymethyl group, a 2-(cyanoethoxy)ethyl group, or a cyanoethoxymethyl group; and X represents a structure represented by any one of Formula B-1 to Formula B-5 shown in the description.

A nucleoside derivative represented below, or a salt thereof. ##STR00001##
(In (1), R.sup.1 represents a hydrogen atom, a hydroxyl group or a protected group, and in (2), X represent a halogen atom. In (1) and (2), R.sup.2 and R.sup.4 each represent a hydrogen atom, a hydroxyl protecting, phosphate, or protected phosphate group, or —P(═O).sub.nR.sup.5R.sup.6 (n is 0 or 1, R.sup.5 and R.sup.6 each representing a hydrogen atom, hydroxyl, protected hydroxyl, mercapto, protected mercapto, lower alkoxy, cyano lower alkoxy, amino or substituted amino group, when n is 1, R.sup.5 and R.sup.6 are not both hydrogen atoms), R.sup.3 represents NHR.sup.7 (R.sup.7 represents a hydrogen atom, alkyl, alkenyl or protecting group for an amino group), an azide, amidino or guanidino group, each having a linking group (when R.sup.7 is hydrogen atom, the linking group is an alkylene group), and B represents any of a purine-9-yl, 2-oxo-pyrimidin-1-yl, substituted purine-9-yl or substituted 2-oxo-pyrimidin-1-yl group).

Embodiments for the synthesis of sensitive oligonucleotides as well as insensitive oligonucleotides are provided. Sulfur-based groups are used for the protection of exo-amino groups of nucleobases, phosphate groups and 2′-OH groups, and as cleavable linker for linking oligonucleotides to a support. Oligonucleotide syntheses are achieved under typical conditions using phosphoramidite chemistry with important modifications. To prevent replacing sulfur-based protecting groups by acyl groups via cap-exchange, special capping agents are used. To retain hydrophobic tag to assist RP HPLC purification, special phosphoramidites are used in the last synthetic cycle. With the sulfur-based groups for protection and linking, oligonucleotide deprotection and cleavage are achieved via oxidation followed by beta-elimination under mild conditions. Therefore, besides for insensitive oligonucleotide synthesis, the embodiments of the invention are capable for the synthesis of oligonucleotide analogs containing sensitive functional groups that cannot survive the harsh conditions used in prior art oligonucleotide synthesis technologies.

An oligonucleotide having a nucleotide residue or a nucleoside residue represented by formula (I) {wherein X.sup.1 is an oxygen atom or the like, R.sup.1 is formula (IIA) (wherein R.sup.5A is halogen or the like, and R.sup.6A is a hydrogen atom or the like), formula (IVA) (wherein Y.sup.3A is a nitrogen atom or the like, and Y.sup.4A is CH or the like), or the like, R.sup.2 is a hydrogen atom, hydroxy, halogen, or optionally substituted lower alkoxy, and R.sup.3 is a hydrogen atom or the like, or formula (VI) (wherein n2 is 1, 2 or 3)} at the 5′ end thereof, wherein the nucleotide residue or the nucleoside residue binds to an adjacent nucleotide residue through the oxygen atom at position 3, is provided.

##STR00001##

The invention relates to a compound of the formula:

##STR00001##

salts thereof, pharmaceutical compositions thereof, as well as methods of treating or preventing HIV in subjects.

Disclosed herein are nucleotide analogs, methods of synthesizing nucleotide analogs and methods of treating diseases and/or conditions such as a HCV infection with one or more nucleotide analogs.

Disclosed herein are nucleotide analogs, methods of synthesizing nucleotide analogs and methods of treating diseases and/or conditions such as a HCV infection with one or more nucleotide analogs.

The present disclosure provides novel anhydrate crystalline Forms 1 and 4 of 4′-Ethynyl-2-fluoro-2′-deoxyadenosine and pharmaceutical compositions thereof, each of which may be useful for the inhibition of HIV reverse transcriptase, the treatment or prophylaxis of HIV infection and/or the treatment, prophylaxis and/or delay in the onset or progression of AIDS or ARC.

The present disclosure provides novel anhydrate crystalline Forms 1 and 4 of 4′-Ethynyl-2-fluoro-2′-deoxyadenosine and pharmaceutical compositions thereof, each of which may be useful for the inhibition of HIV reverse transcriptase, the treatment or prophylaxis of HIV infection and/or the treatment, prophylaxis and/or delay in the onset or progression of AIDS or ARC.