Chiral peptide nucleic acid monomers and oligomers

DETAILED DESCRIPTION What is claimed is: 1.
A peptide nucleic acid monomer having the formula: ##STR5## wherein: B is a naturally or non-naturally ocurring nucleobase; n is 0, 1, 2, or 3; and at least one of C.
alpha.
or C.
beta.
is in the S configuration.
2.
The monomer of claim 1 wherein C.
alpha.
and C.
beta.
are in the S configuration.
3.
The monomer of claim 1 wherein n is 2.
4.
A peptide nucleic acid monomer having the formula: ##STR6## wherein: B is a naturally or non-naturally ocurring nucleobase; and at least one of C.
alpha.
or C.
beta.
is in the S configuration.
5.
The monomer of claim 4 wherein C.
alpha.
and C.
beta.
are in the S configuration.
6.
A peptide nucleic acid oligomer complementary to a target molecule, said oligomer comprising at least one peptide nucleic acid monomer having a (2-aminoethyl)glycine backbone, wherein the C.
alpha.
and C.
beta.
carbons of said monomer form part of an alicyclic structure which renders said C.
alpha.
and C.
beta.
carbons chiral, said monomer being incorporated into the peptide nucleic acid oligomer at a position corresponding to a region of variability in the target molecule.
7.
An oligomer comprising at least two peptide nucleic acid monomers, at least one of said peptide nucleic acid monomers having the structure: ##STR7## wherein: B is a naturally or non-naturally ocurring nucleobase; at least one of C.
alpha.
or C.
beta.
is in the S configuration; Q is --OH, a carbonyl protecting group, or a covalent bond; I is H, an amino protecting group, or a covalent bond; and n is 0, 1, 2, or 3.
8.
The oligomer of claim 7 wherein C.
alpha.
and C.
beta.
are in the S configuration.
9.
The oligomer of claim 7 wherein n is 2.
10.
A peptide nucleic acid monomer having the formula: ##STR8## wherein: B is adenine, cytosine, guanine, thymine, or uracil; n is 0, 1, 2, or 3; and at least one of C.
alpha.
or C.
beta.
is in the S configuration.
11.
A peptide nucleic acid monomer having the formula: ##STR9## wherein: B is adenine, cytosine, guanine, thymine, or uracil; and at least one of C