| 摘要 |
NEW MATERIAL:A compound shown by formula I [R<1> is halogen, lower alkane sulfonyloxy or lower alkyl; R<2> is group shown by formula II (X<1> is halogen; R<4> is esterified carboxy); R<3> is azido or phthalimido]. EXAMPLE:Benzyl 2-( 2'-S-mesyloxymethyl-3'-S-phthalimido-4'-oxo ) azetidinyl-2- bromo-3-oxobutylate. USE:A synthetic intermediate for 2-oxoisocephem derivative of antibiotic. PREPARATION:A compound shown by formula III is reacted with a halogenating agent (e.g. halogen or N-halogenated succinimide) in the presence or absence of a solvent (e.g. methylene chloride) at 0-50 deg.C to give a compound shown by formula I. |
