| 摘要 |
NEW MATERIAL:A compound shown by the formula I [R is (halogen-substituted) 1-5C alkyl, substituted silyl, benzyl, benzhydryl, or trityl (with the proviso that phenyl nucleus of the group may be replaced with methyl, methoxy, or nitro)]. EXAMPLE:(+ or -)-6,7-Cis-7-phthalimido-1-azabicyclo[4, 2, 0]oct-2-ene-3-formyl-3-oxo-2- carboxylic acid tertiary butyl ester. USE:An intermediate for antibacterial compound. PREPARATION:A nitro derivative shown by the formula III is reacted with titanium trichloride in a mixed system of an aqueous solution and an organic solvent such as methanol, THF, DMF, etc. at 0-30 deg.C, to give an aldehyde derivative shown by the formula IV. This compound is then treated with a halogenating agent such as pyrrolidone hydrotribromide, etc., and a halogen is introduced into the treated compound at alpha-position. The resultant compound is dehydrohalogenated with a base.
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