Asymmetrized tris(hydroxymethyl)methane as precursor of N- and O-containing 6-membered heterocycles through ring-closing metathesis

A novel synthetic application of asymmetrized tris(hydroxymethyl)rnethane (THYM*) 1, obtained in both enantiomeric forms in high e.e. via a chemoenzymatic procedure, is described. Starting from the common precursor 3, N- and O-containing 6-membered heterocycles have been prepared exploiting ring-closing metathesis as the key step. Possible elaborations of the double bond in 6 and 28 have been explored and, in the case of 28, conversion into the glycosidase inhibitor isofagomine 53 has been achieved.