Synthesis of new stereoisomeric nitrate esters derived from isosorbide-mononitrate II: Bicyclic delta-lactams and tetrahydrofuran derivatives

Abstract

The synthesis of the diastereomeric nitrate esters (3R,4R)-(2-hydroxy-4-nitrooxytetrahydrofuran-3-yloxy)acetonitrile (5b) and (3R,4S)-(2-hydroxy-4-nitrooxytetrahydrofuran-3-yloxy)acetonitrile (9) was achieved by the Beckmann fragmentation of 1,4:3,6-dianhydro-D-glucitol-5-(or -2-)nitrate-2-(or -5-)ketoximes (4b and 8), respectively. The bicyclic delta -lactams, (1R,6R,7R)-N-methyl-7-endo-nitrooxy-3-oxo-5,9-dioxa-2-azabicy-clo[4.3.0]nonane (15b) and the stereoisomer (1R,6R,7S)-7-exo-nitrooxy-3-oxo-5,9-dioxa-2-azabicyclo[4.3.0]nonane (18b) were prepared by the Beckmann rearrangement of nitrones 14b and 17b, respectively. The stereoisomeric delta -lactams, N-methyl-7-endo-benzoyloxy- (15a) and N-methyl-7-exo-benzoyloxy-3-oxo-5,9-dioxa-2-azabicyclo[4.3.0]nonane (18a) were prepared from the corresponding nitrones 14a and 17a, respectively.