A new
route was developed for construction of the oxathiolane intermediate
used in the synthesis of lamivudine (3TC) and emtricitabine (FTC).
We developed the presented route by constraining ourselves to low-cost,
widely available starting materials—we refer to this as supply-centered
synthesis. Sulfenyl chloride chemistry was used to construct the framework
for the oxathiolane from acyclic precursors. This bond construction
choice enabled the use of chloroacetic acid, vinyl acetate, sodium
thiosulfate, and water to produce the oxathiolane.