3′-Deoxynucleosides have demonstrated profound biochemical utility, including in our recent work on the use of aminoacyl thio-tRNAs for in vitro translation. Though our preparation of 3′-(2-pyridyldithio)-3′-deoxyadenosine─a key synthetic precursor en route to aminoacyl thio-tRNAs─followed robust prior precedents, an unrelated recent structural revision prompted us to validate the regioselectivity of our route further. Here we provide confirmatory evidence for the structure of 3′-(2-pyridyldithio)-3′-deoxyadenosine and downstream analogues via synthetic convergence with a 3′-deoxynucleoside antibiotic, cordycepin, and concomitant MicroED analysis.

The ribosomal incorporation of backbone-modified amino acid analogs into peptides and proteins enables the programmed synthesis of sequence-defined biopolymers with tunable properties. However, the su...