First synthesis of fully modified 4'-selenoRNA and 2'-OMe-4'-selenoRNA based on the mechanistic considerations of an unexpected strand break.

This study investigated oligonucleotide (ON) synthesis containing 4'-selenoribonucleoside(s) under standard phosphoramidite conditions. Careful operation using a manual ON synthetic system revealed that an unexpected strand break occurred to afford a C2-symmetric homodimer as a byproduct. In addition, this side reaction occurred during I2 oxidation.

Poly[bis-(μ(3)-dodecyl sulfato)-calcium].

In the title compound [Ca(C(12)H(25)O(4)S)(2)](n), the unique Ca(II) ion lies on an inversion center and is coordinated in a slightly distorted octa-hedral environment by six O atoms from dodecyl sulfate anions. The crystal structure is based on hydro-carbon (dodecyl sulfate) layers which sandwich the Ca(II) ions. Within the layers, the hydro-carbon zigzag chains are parallel to one another and inter-act via van der Waals forces.