Thermolabile hydroxyl protecting groups and methods of use

A hydroxyl-protected alcohol of the formula Pg-O—R, wherein Pg is a protecting group of the formula:

• wherein:
• A is a 2-pyridyl group of the formula:
• Z is CH2 or NR1;
• R1, R2, R2′, R3 and R3′ are the same or different and each is H, a saturated alkyl, an unsaturated alkyl, an aryl, a saturated alkyl comprising an aryl substituent, or an unsaturated alkyl comprising an aryl substituent, wherein the saturated alkyl, unsaturated alkyl and aryl portions are optionally substituted;
• R4, R5, R6, and R7 are the same or different and each is H, an amino, a monoalkylamino, a dialkylamino, a hydroxy, an alkoxy, a halogen, an amide, a saturated alkyl, an unsaturated alkyl, an aryl, a saturated alkyl comprising an aryl, or an unsaturated alkyl comprising an aryl;
• W is CO;
• and
• R is the organic residue of the hydroxyl-protected alcohol of the formula:
• wherein:
• Q is a nucleoside, an oligonucleotide, or an oligomer comprising a nucleoside;
• X is O, S or Se;
• R8 is H, a protecting group or a solid support;
• R9 is H or a protecting group;
• B is a labeling group, a saturated alkyl, an unsaturated alkyl, a cycloalkyl, an aryl, a heteroaryl comprising from 5 to about 10 atoms in the ring skeleton thereof, a heterocycloalkyl comprising from 3 to about 10 atoms in the ring skeleton thereof, a saturated alkyl comprising an aryl substituent, an unsaturated alkyl comprising an aryl substituent, an amino, an alkylamino, a dialkylamino, a purine, a pyrimidine, adenine, guanine, cytosine, uracil, or thymine, wherein B is unsubstituted or substituted with one or more substituents, which are the same or different, selected from the group consisting of a nucleobase protecting group, R10, OR10, NHR10, NR10R11, N═CH—NR10aR11a, N═C(alkyl)-NR10aR11a, CN, NO2, N3, and a halogen, wherein R10 and R11 are the same or different and each is H, a saturated alkyl, an unsaturated alkyl, a keto, or a thioketo, and R10a and R11 are the same or different and each is a saturated alkyl or an unsaturated alkyl, or, R10a and R11a, together with the nitrogen atom to which they are bonded, form a heterocycle containing 3 to about 7 atoms in the ring skeleton thereof;
• and
• E is H, a halogen, OR12, NHR12, or NR12R13, wherein R12 and R13 are the same or different and each is H, a protecting group, a saturated alkyl, an unsaturated alkyl, a keto or a thioketo;
• wherein the protecting group is thermolabile.

A hydroxyl-protected alcohol of the formula Pg-O—R, wherein Pg is a protecting group of the formula:

• wherein:
• A is a 2-pyridyl group of the formula:
• Z is CH2 or NR1;
• R1, R2, R2′, R3 and R3′ are the same or different and each is H, a saturated alkyl, an unsaturated alkyl, an aryl, a saturated alkyl comprising an aryl substituent, or an unsaturated alkyl comprising an aryl substituent, wherein the saturated alkyl, unsaturated alkyl and aryl portions are optionally substituted;
• R4, R5, R6, and R7 are the same or different and each is H, an amino, a monoalkylamino, a dialkylamino, a hydroxy, an alkoxy, a halogen, an amide, a saturated alkyl, an unsaturated alkyl, an aryl, a saturated alkyl comprising an aryl, or an unsaturated alkyl comprising an aryl;
• W is CO;
• and
• R is the organic residue of the hydroxyl-protected alcohol,
• wherein when Z is CH2, at least one of R2, R2′, R3, R3′, R4, R5, R6, and R7 is not H, and
• wherein the protecting group is thermolabile.

A hydroxyl-protected alcohol of the formula Pg-O—R, wherein Pg is a protecting group of the formula:

• wherein:
• A is a 2-pyridyl group of the formula:
• Z is CH2 or NR1;
• R1, R2, R2′, R3 and R3′ are the same or different and each is H, a saturated alkyl, an unsaturated alkyl, an aryl, a saturated alkyl comprising an aryl substituent, or an unsaturated alkyl comprising an aryl substituent, wherein the saturated alkyl, unsaturated alkyl and aryl portions are optionally substituted;
• R4, R5, R6, and R7 are the same or different and each is H, an amino, a monoalkylamino, a dialkylamino, a hydroxy, an alkoxy, a halogen, an amide, a saturated alkyl, an unsaturated alkyl, an aryl, a saturated alkyl comprising an aryl, or an unsaturated alkyl comprising an aryl;
• W is CO;
• and
• R is the organic residue of the hydroxyl-protected alcohol,
• wherein R is not a low molecular weight aromatic alcohol, and
• wherein the protecting group is thermolabile.