Polynucleotide reagents containing modified deoxyribose moieties, and associated methods of synthesis and use

A reagent having the structural formula ##STR12## wherein:

• R.sup.1 is selected from the group consisting of hydrogen, acid-sensitive, base-stable protecting groups and acyl capping groups;
• R.sup.2 is a phosphorus derivative selected to enable addition of the reagent to a molecular species containing a free hydroxyl group, or is a linkage to a solid support;
• R.sup.3 is selected from the group consisting of hydrogen, hydroxyl, sulfhydryl, halogeno, amino, alkyl, allyl, -OR.sup.6 wherein R.sup.6 is alkyl, allyl, silyl or phosphate;
• R.sup.4 is either hydrogen or -(CH.sub.2).sub.m OR.sup.7 wherein R.sup.7 is alkyl or -(CO)R.sup.8, R.sup.8 is alkyl and m is an integer in the range of 0 to 12 inclusive;
• R.sup.5 is -A-Z-X(R.sup.9)n;
• A is oxygen, sulfur or methylene;
• Z is arylene, C.sub.6 -C.sub.18 aralkylene or C.sub.1 -C.sub.12 alkylene containing 0 to 6 heteroatoms selected from the group consisting of O, S, N, Si and Se and 0 to 6 linkages selected from the group consisting of -CO-, -COO-, -CONH-, -NHCO-, -S-S-, -SO.sub.2 -, -CH(OH)-CH(OH)-, -CH(OR.sup.15)-CH(OR.sup.15)-,-O-PO(O.sup.31 )-O-, -O-P)(R.sup.15)-, -O-P)(OR.sup.15)-O-, -O-P)(OR.sup.15)-R.sup.16 - and -PO(OR.sup.15)-O-R.sup.16 - in which R.sup.15 is lower alkyl and R.sup.16 is lower alkylene, and, if Z is aralkylene or alkylene, containing 0 to 3 unsaturated bonds;
• X is selected from the group consisting of -NH-, -CONH-, -NHCO-, -CO-, -S- and -Si.ident.;
• R.sup.9 is hydrogen, a protecting group, a detectable label, or, unless X is -Si.ident., a solid support;
• and
• n is 1 when X is -NH-, -CONH-, -NHCO-, -CO-, or -S-, and is 3 when X is -Si.ident.,
• with the proviso that if R.sup.2 represents a linkage to a solid support, R.sup.9 is hydrogen, a protecting group, or a detectable label.