New RNA Purine Building Blocks, 4′‐Selenopurine Nucleosides: First Synthesis and Unusual Mixture of Sugar Puckerings

Writer's blocks: The first synthesis of RNA purine building blocks, 4′-selenoadenosine and 4′-selenoguanosine was achieved from D-ribose by regioisomeric rearrangement, which was confirmed by X-ray crystallography. 4′-Selenoadenosine exists in an unusual mixture of north and south conformers in the solid state. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.