The reactions of 2,3-dihydro-1,5-benzothiazepines with ethoxyearbonylcarbene undergo complex rearrangements to produce rlng-opening and ring contraction products. Previously it was presumed that the different products were formed via different mechanisms depending on the kind of substituents at the 2-position of 1,5-benzothiazepines. However, on the basis of the further detailed investigation, it was found that all 1,5-benzothiazepines can undergo the same rearrangement to yield both ring-opening and ring contraction products.
Several 2-aminoalkanesulfonic acids have been found in many mammalian tissues till now and are involved in various and important physiological processes. Recently attention has been paid to their syntheses for studies of these physiological processes, the structural modification of natural peptides to overcome the limitations associated with their development as therapeutically useful agents, and information on the nature and mechanism of the peptide-receptor interactions.……
