| 摘要 |
<p>NEW MATERIAL:A compound of formula I (X is amino, azide, phthalide; R1 is hydroxyl, halogen, 1-4C alkanoyloxy, benzoyloxy which may be substituted with chlorine; R2 is H, hydroxyl, halogen, 1-4C lower alkanoyloxy; benzoyloxy which may be substituted with chlorine; R3 is H, carboxyl-protecting group, where cases in which R1 is halogen and R2 is H, one of R1 and R2 is hydroxyl and the other is 1-4C alkanoyl or benzoyloxy which may be substituted with chlorine are excluded; further in case that R1 is hydroxyl and R2 is halogen, R2 is bromine). EXAMPLE:(+ or -)cis-2-tert.-Butyloxycarbonyl-4alpha-hydroxy-5beta-chloro-7beta-azide -1-azabicyclo[4,2,0]oct-2-ene-8-one. USE:Antibacterial. PREPARATION:The double bond of formula II (Xa is azide or phthalimide) is oxidized with quaternalized osmium and hydrogen peroxide into a diol of formula III, then intramolecular cyclization is effected with a base to give the compound of formula I (where R1 and R2 are hydroxyl; X is Xa).</p> |
