ChemInform Abstract: Synthesis of 'α-Homogalactostatin' and of Its 1,N-Anhydro Derivative

α-Homogalactostatin 2 was prepared in 10 steps from 2,3,4,6-tetra-O-benzyl- d -galactose by way of a Wittig chain extension and a mercuricyclization. The synthesis of 2 was assisted by the unexpected participation of the nitrogen protecting group (benzyl carbamate) during iododemercuration. Intermediate 10 was converted in 2 steps into the 1,N-anhydro derivative of 2, compound 3, a potential inactivator of galactosidases.