4-spirocyclopropaneisoxazolidine carboxylate, 1,3-amino alcohols, lactones, cleavage of the N-O bond 1, 3 - Dipolar cycloaddition of nitrones to the double carbon – carbon bond of acceptor ring substituted methylenecyclopropanes affords thermally stable regioisomeric 4 - spirocyclopropaneisoxazolidine. Cleavage of the N - O bond in 4 - spirocyclopropaneisoxazolidine with ester groups on the three - membered ring by the action of activated zinc dust in acetic acid gives the corespoding 1, 3 - amino ancohols containing cyclopropyl ring, whose subsequent cyclization under the reaction conditions yield bi- or tri - cyclic lactams or lactones with retention of the three - membered ring - structural moieties of antibiotics and biologically active compounds. |
