| 摘要 |
NEW MATERIAL:A 3-(1'-hydroxyethyl)-4-(beta,beta-disubstituted ethyl)-2-azetidinone shown by the formula II (R1 is alkyl). EXAMPLE:3-(1'-Hydroxyethyl)-4-(beta,beta-dimethoxyethyl)-2-azetidinone. USE:An intermediate for a novel antibiotic thienamycin [3-(2-aminoethylthio)-6-(1- hydroxyethyl)-7-oxo-1-azabicyclo(3,2,0)hepto-2-ene-2-carboxylic acid]. The use of ?the intermediate can prepare thienamycin industrially advantageously. PROCESS:A 3-nitropropanaldimethylacetal shown by the formula III is reacted with a methyl crotonate shown by the formula IV (R2 and R3 are lower alkyl) to give an isoxazoline derivative shown by the formula V or VI, which is reduced under moderate pressure to prepare an amine derivative shown by the formula VII. This compound finally undergoes a Grignard reaction to give a compound shown by the formula II. |
