Patent ID: 7718810

Claim:
A compound of the formula I: wherein: R w and R x are each, independently, H, alkyl or substituted alkyl; R a and R b are each, independently, H, a protecting group, a protected or unprotected nucleosidyl moiety, a protected or unprotected nucleosidyl moiety attached through a phospholinker, or a protected or unprotected oligonucleotidyl moiety; Y is alkylene, cycloalkylene, arylene, heteroarylene, arylalkylene, alkarylene, or alkylenearylalkylene; E is a bond, (CH 2 ) i C(═O) or C(═O)(CH 2 ) j C(═O) wherein i is from 0 to 20 and j is from 1 to 20; and SM is a support medium.