ChemInform Abstract: Stereoselective Electrophilic Cyclizations of δ‐Aminoalkenes Derived from Carbohydrates; Synthesis of Polyhydroxypiperidines.

Abstract

Stereoselective Electrophilic Cyclizations of δ-Aminoalkenes Derived from Carbohydrates; Synthesis of Polyhydroxypiperidines.-Electrophilic cyclization of glucose-derived δ-aminoalkene (I) affords a mixture of D-gluco-and L-ido-configured polyhydroxypiperidines. Thus, iodocyclization of compound (I) with excess iodine or N-iodosuccinimide predominantly gives the D-gluco derivative (II) probably due to steric reasons. A similar result is obtained for the cyclization with mercury ions in aqueous THF solution furnishing D-gluco derivative (IV). In contrast, in the presence of excess mercury salt under non-aqueous conditions a change in stereoselectivity to the L-ido analogue (V) is observed, which is proposed to be a result of chelation control. -(HUEGEL, HELMUT M.; HUGHES, ANDREW B.; KHALIL, KHADIJEH; Aust.