Process for the synthesis of oligomeric compounds

DETAILED DESCRIPTION What is claimed is: 1.
A method for the preparation of an oligomeric compound having a moiety of Formula I: ##STR38## wherein: X.
sub.
4 is Z or H; Z is CN, halogen, alkaryl, substituted sulfoxyl, substituted sulfonyl, or a substituted thio group, wherein said substituent is alkyl, aryl, or alkaryl; and X.
sub.
1 is O or S; comprising the steps of: (a) providing a compound having the Formula II: ##STR39## wherein: each R.
sub.
1, is, independently, H, --OH, --F, or --O--X.
sub.
3 --D; X.
sub.
3 is alkylenyl having from 1 to 10 carbons; D is H, amino, protected amino, alkyl substituted amino, imidazolyl, or (--O--X.
sub.
3).
sub.
p H where p is 1 to about 10; each X.
sub.
2 is O or S; R.
sub.
3 is selected from the group consisting of hydrogen, a hydroxyl protecting group, and a linker connected to a solid support; each B, independently, is selected from the group consisting of a naturally occurring nucleobase, a non-naturally occurring nucleobase, a protected naturally occurring nucleobase, and a protected non-naturally occurring nucleobase; n is 0 to about 50; each Q is --X.
sub.
1 H or ##STR40## R.
sub.
5 is selected from the group consisting of --N(R.
sub.
6).
sub.
2, a heterocycloalkyl ring containing from 4 to 7 atoms, and having up to 3 heteroatoms selected from nitrogen, sulfur, and oxygen, and a heterocycloalkenyl ring containing from 4 to 7 atoms, and having up to 3 heteroatoms selected from nitrogen, sulfur, and oxygen; and R.
sub.
6 is straight or branched chain alkyl having from 1 to 10 carbons; and (b) reacting the compound of Formula II with a compound having Formula III: ##STR41## wherein R.
sub.
3a is hydrogen; and R.
sub.
2 is a hydroxyl protecting group, or a linker connected to a solid support, provided that R.
sub.
2 and R.
sub.
3 are not both simultaneously a linker connected to a solid support; to form the oligomeric compound.
2.
The method of claim 1 further comprising the step of oxidizing or sulfurizing the oligomeric compound to form a further compound having Formula III, wherein R