Sugar lactams and lactim ethers, useful precursors of cyclic amidines, from intramolecular nucleophilic displacements

Article abstract of DOI:10.1016/S0040-4039(97)00959-3

The cyclisation of the conjugate base of N-aryl-2,3:5,6-di-O-isopropylidene-4-O-methanesulfonyl-D- gulonamides gave the D-allonolactam acetals. Sodium methoxide-promoted cyclisation of 2,3:5,6-di-O-isopropylidene-4-O-methanesulfonyl-D-mannononitrile gave the D-talonolactim ether. Tetrazole formation without isolation of the intermediate azide was illustrated by the conversion of the aforementioned nitrile sulfonate into the D-talonotetrazole. Cyclic amidines were prepared from the lactam and lactim ether derivatives. The D-allono derivatives were also converted into D-ribono-1,4 lactam and amidine derivatives.