General access to polyhydroxylated nortropane derivatives through hetero Diels-Alder cycloaddition. Part II: Synthesis of (±) calystegine B2

Article abstract of DOI:10.1016/S0040-4020(96)00948-9

Celystegine B₂ was prepared by the intramolecular cyclisation of a polyhydroxylated 4-aminocycloheptanone. This intermediate results from a heterocycloaddition between an acylnitroso compound and a cyclohepta-1,3-diene. The diene is in turn obtained from iron-complexed tropone.