A novel deaminative cyclization of aminoglycoside. Synthesis of a kanamycin B variant having 2-oxa-5-azabicyclo[2,2,2]oct-1,5-diene ring

The 3′,5′-diene derivative of kanamycin B ($\text{2}$) was obtained from a 4′-ene derivative of kanamycin B ($\text{1}$) by treatment with trimethyl orthoacetate. Formation of the title compound ($\text{4}$) from $\text{2}$ deaminative cyclization with sodium methoxide followed by treatment with trifluoroacetic acid was described.