Synthesis of (+)-Galactostatin and (+)-1-Deoxygalactostatin Utilizing L-Quebrachitol as a Chiral Building Block.

The stereoselective conversion of the naturally occurring optically active cyclitol, L-quebrachitol 1, into galactosidase inhibitors, (+)-galactostatin 2 and (+)-1-deoxygalactostatin 3 is described; the key steps in this synthesis are (i) stereoselective introduction of an azido function and (ii) regioselective ring cleavage of the cyclohexane ring of 1 by way of the Baeyer–Villiger reaction.