Cyclobutyl oligonucleotide surrogates

Claim 2

An oligonucleotide surrogate comprising at least two cyclobutyl moieties wherein each of said cyclobutyl moieties include a purine or pyrimidine heterocyclic base attached at a C-1 cyclobutyl position and wherein said cyclobutyl moieties are joined through a C-2, C-3, or C-4 position on a first of said cyclobutyl moieties and a C-2, C-3, or C-4 position on a second of said cyclobutyl moieties by a linkage that contains 4 or 5 consecutive, covalently-bound atoms selected from the group consisting of C, N, O, S, Si and P.

Claim 3

An oligonucleotide surrogate of claim 1 wherein said purine or pyrimidine heterocyclic base is a naturally-occurring or synthetic purin-9-yl, pyrimidin-1-yl or pyrimidin-3-yl heterocyclic base.

Claim 4

An oligonucleotide surrogate of claim 2 wherein said purine or pyrimidine heterocyclic base is adenine, guanine, cytosine, thymine, uracil, 5-methylcytosine, hypoxanthine or 2-aminoadenine.

Claim 5

An oligonucleotide surrogate of claim 1 wherein each of said linkages connects two of the cyclobutyl moieties at a C-3 position of the cyclobutyl moieties.

Claim 6

An oligonucleotide surrogate of claim 1 wherein each of said linkages comprises a linkage that is 5 atoms long that joins two of the cyclobutyl moieties.

Claim 7

An oligonucleotide surrogate of claim 5 wherein each of said linkages is of the structure: L.sub.1 -L.sub.2 -L.sub.3 wherein: L 1 and L 3 are CH 2 ; and L 2 is phosphodiester, phosphorothioate, phosphoramidate, phosphotriester, C 1 -C 6 alkyl phosphonate, phosphorodithioate, phosphonate, carbamate, sulfonate, C 1 -C 6 -dialkylsilyl or formacetal.

Claim 8

An oligonucleotide surrogate of claim 5 wherein each of said linkages is of the structure: L.sub.1 -L.sub.2 -L.sub.3 where: L 1 and L 3 are CH 2 ; and L 2 is phosphodiester or phosphorothioate.

Claim 9

An oligonucleotide surrogate of claim 1 wherein each of said linkages comprises a linkage that is 4 atoms long that joins two of the cyclobutyl moieties.

Claim 10

An oligonucleotide surrogate of claim 8 wherein each of said linkages is of the structure: L.sub.4 -L.sub.5 -L.sub.6 -L.sub.7 where: (a) L 4 and L 7 are CH 2 ; and L 5 and L 6 , independently, are CR 1 R 2 , C═CR 1 R 2 , C═NR 3 , C═O, C═S, O, S, SO, SO 2 , NR 3 or SiR 4 R 5 ; or (b) L 4 and L 7 are CH 2 ; and L 5 and L 6 , together, are CR 1 ═CR 2 , C.tbd.C, part of a C 6 aromatic ring, part of a C 3 -C 6 carbocyclic ring or part of a 3, 4, 5 or 6 membered heterocyclic ring; or (c) L 4 -L 5 -L 6 -L 7 , together, are CH═N--NH--CH 2 or CH 2 --O--N═CH; where: R 1 and R 2 , independently, are H, OH, SH, NH 2 , C 1 -C 10 alkyl, C 1 -C 10 substituted alkyl, C 1 -C 10 alkenyl, C 7 -C 10 aralkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkoxy, C 1 -C 6 alkylamino, C 7 -C 10 aralkylamino, C 1 -C 10 substituted alkylamino, heterocycloalkyl, heterocycloalkylamino, aminoalkylamino, polyalkylamino, halo, formyl, keto, benzoxy, carboxamido, thiocarboxamido, ester, thioester, carboxamidino, carbamyl, ureido, guanidino, or an RNA cleaving group; R 3 is H, OH, NH 2 , C 1 -C 6 alkyl, substituted lower alkyl, alkoxy, lower alkenyl, aralkyl, alkylamino, aralkylamino, substituted alkylamino, heterocycloalkyl, heterocycloalkylamino, aminoalkylamino, polyalkylamino, or a RNA cleaving group; and R 4 and R 5 , independently, are C 1 -C 6 alkyl or alkoxy.

Claim 11

An oligonucleotide surrogate compound of claim 8 wherein each of said linkages is CH═N--NH--CH 2 , CH 2 NH--NH--CH 2 , CH 2 -O--NH--CH 2 or CH 2 --O--N═CH.

Claim 12

An oligonucleotide surrogate of claim 4 further including a substituent group attached to at least one of the cyclobutyl moieties at a C-2 position or a C-4 position of the cyclobutyl moieties.

Claim 13

An oligonucleotide surrogate of claim 11 wherein said substituent group is halogen, C 1 -C 10 alkoxy, allyloxy, C 1 -C 10 alkyl or C 1 -C 10 alkylamine.

Claim 14

An oligonucleotide surrogate of claim 12 wherein said substituent group is positioned trans to said heterocyclic base.