WAng J, et al., Arch. Pharm. Chem. Life Sci. 2017, 350, e1600307
We made the 3-phenylvinylsufone derivative of ethyl acrylate as a model compound for deprotection studies that will start later this week. My student recently found a paper in which they deprotected this very compound with lithium hydroxide, THF/ H2O, at room temperature for one hour. This is step iii of Scheme 2 of their paper.
I think that there might be an error in the reagent of step i in their scheme 2 (I don't see how the thiol can form a bond to an unactivated carbon; maybe they used ethyl propynoic acid, but I am just guessing). Their written explanation of step iii has an unfamiliar use of the term hydraulic: "To a solution of an appropriate intermediate 18a–d (7.1 mmol) dissolved in THF/H2O (25 mL, 3:2) was added 2 eq of lithium hydroxide monohydrate, and the resulting suspension was stirred for 1 h at room temperature. Then, most of the solvent was evaporated, and the residue was poured into water (5mL). The aqueous layer was acidified by addition of 6 N hydrochloric acid solutions until pH 3, and then separated out from hydraulic. The mixture was filtered to collected substituted acids (19a–d)."
It may be that upon acidification, that the product precipitates from aqueous solution. Possibly "hydraulic" was a spelling error of some kind. Despite these nitpicks, I think that there paper is very encouraging news, in that a mild alkaline hydrolysis is not enough to destroy the vinyl sulfone group.