Highly Z-selective synthesis of 1,3-oxathiol-2-ylidenes and 4-methylene-oxazolidine-2-thiones via atom-specific 5-exo-dig cyclization of propargyl alcohol with isothiocyanate

Highly Z-selective synthesis of 1,3-oxathiol-2-ylidenes and 4-methylene-oxazolidine-2-thiones via atom-specific 5-exo-dig cyclization of propargyl alcohol with isothiocyanate