3,3-Diphenyl-2-Morpholinone Derivatives Of 2-Amino-2-Deoxy-D-Allose.

A new cyclic protective group has been fused to the cis amino alcohol group of benzyl 2-amino-3,5-o-benzylidene-2-deoxyβ-D-Allopyranoside, by way of a unique rearrangements mechanism. To establish the 2-morpholinone structure, chemical studies, such as reduction and acetylation were conducted. Comparative spectroscopic studies using ir, pmr, and C-13 nmr confirmed the assigned structures. The 2-morpholinone ring was cleaved by mild alkaline hydrolysis and could be closed again with acetic anhydride in pyridine. An oxazolidinone derivation of benzyl 2-amino-4,6-o-benzylidene-2-deoxyβ-D-allopyranoside was prepared in a quantitative yield by a modification of a known method. Protective group properties of the oxazolidinone were studied prior to the examination of the 2-morpholinone cyclic protective group. The selective removal of the benzyl aqlycon was achieved in excellent yield by catalytic hydrogenation, for both morpholinone and oxazolidinone protected benzyl-β-D-Allopyranoside. The selective removal of the 4,6-o-benzylidone group in presence of a 2-morpholinone ring was possible in high yield. The cleavage of the 2-morpholinone protective group was accomplished in two steps. Mild alkaline hydrolysis cleaved the ester function of the ring and mild acidic hydrolysis cleaved its amino function