OLIGOMER BONDED TO NUCLEIC ACID

PROBLEM TO BE SOLVED: To obtain the subject new compound having new C-branches and N-branches, suitable for suppressing the expression of genes, exhibiting an antiviral property and useful for treating virus-infected diseases or cancers. SOLUTION: A compound of formula I [A is CO, etc.; B is thymine, acetyl, etc.; C is CH, etc.; D is NH, etc.; E is NRR' (R, R' are each OH, methyl, etc., F is CH2 , etc.; G is NH, etc.; H is CR R (R is H, methyl; R is H, a 1-4C alkyl, etc.), etc.; L is (CH2 )p ((p) is 0-2), etc.; M is CH2 , etc.; Q is OH, O, etc.; T is hydroxyl group, etc.; (r) is 0, 1; (s) is 1-30], e.g. δ-N-Boc-α-N-L-ornithine methyl ester. The compound of formula I is produced e.g. by subjecting δ-N-Boc- protected L-ornithine methyl ester to a reductive amination reaction to introduce a benzyl protecting group, subjecting the obtained compound of formula II to an α-N-methylation reaction, introducing a nucleic acid base to the obtained compound of formula II, and subsequently hydrolyzing the compound of formula IV. The produced compound of formula I is suitable for oligomerization.