Abstract: 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, R1 represents an alkoxy group, —NRN2, a hydroxy group, an aryl group, or an alkyl group, wherein RN each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; n represents an integer from 1 to 5; R3 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.

Abstract: 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, R1 represents an alkoxy group, —NRN2, a hydroxy group, an aryl group, or an alkyl group, wherein RN each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; n represents an integer from 1 to 5; R3 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.

Abstract: Provided a polymerizable compound represented by the following Formula A-1 or Formula A-2: In Formula A-1 or Formula A-2, R1 represents an electron-donating group; n represents an integer from 1 to 5; R2 represents a hydrogen atom, a halogen atom, or —ORO, wherein RO represents a hydrogen atom, an alkyl group, or a protecting group of a hydroxy group; R3 represents a hydrogen atom or a protecting group of a hydroxy group; and X represents a structure represented by any one of Formula B-1 to Formula B-5.

Abstract: Provided a polymerizable compound represented by the following Formula A-1 or Formula A-2: In Formula A-1 or Formula A-2, R1 represents an electron-donating group; n represents an integer from 1 to 5; R2 represents a hydrogen atom, a halogen atom, or —ORO, wherein RO represents a hydrogen atom, an alkyl group, or a protecting group of a hydroxy group; R3 represents a hydrogen atom or a protecting group of a hydroxy group; and X represents a structure represented by any one of Formula B-1 to Formula B-5.

Abstract: A nucleic acid oligomer for RNA hybrid formation, including a structure formed of from 3 to 50 continuous units of at least one unit of a nucleotide unit represented by the following General Formula (1) or a nucleotide unit represented by the following General Formula (2); and having a base length of from 8 bases to 50 bases: in which in the formulae, R1 represents a hydrogen atom, an alkoxy group, an alkenyloxy group, an acyloxy group, a trialkylsilyloxy group, or a halogenyl group, and, in the formulae, each Bs1 independently represents a pyrimidine base that may have a protecting group, a hydrogen atom bonded to a carbon atom at the 5-position of the pyrimidine base may be substituted with a group other than a hydrogen atom, in the formulae, each X independently represents S?Z+ or BH3—Z+, Z+ represents a counter cation, each R2 and R3 independently represents a hydrogen atom, or an alkyl group having from 1 to 10 carbon atoms, and R2 and R3 may be bonded to each other to form a ring.

Abstract: A method for preparing a phosphorothioate RNA based on the oxazaphospholidine method, wherein cyanoethoxymethyl group is used instead of tert-butyldimethylsilyl group as a protective group of 2?-hydroxyl group of RNA.

Abstract: A method for preparing a phosphorothioate RNA based on the oxazaphospholidine method, wherein cyanoethoxymethyl group is used instead of tert-butyldimethylsilyl group as a protective group of 2?-hydroxyl group of RNA.