| 摘要 |
NEW MATERIAL:A compound of formula I (X is O or S; Y is 1-methylhydroxyethylidene, etc.; Z is a H or a protecting group, e.g. an alkali, etc.; R is acetyl, etc.; the part of the dotted line is a single or double bond). EXAMPLE:p-Nitrobenzyl 3-(acetoxymethyl)-6-(R)-(2-oxo-4-methyl-1,3-dioxolan-4-yl)- 7- oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylate. USE:An antimicrobial agent. PROCESS:A silyl group is removed from a compound of formula II, and phosgene is reacted with the resultant compound. The reaction product is then oxidized to give a compound of formula III, which is then reacted with a nucleophilic reagent, etc. and oxidized. The protecting group is then removed to afford a compound of formula IV. A glyoxylic acid ester, etc. is then reacted with the compound of formula IV, and the OH group is substituted by a halogen. The resultant compound is then reacted with triphenylphosphine to afford the compound of formula V, which is then heated to carry out the ring closure and give the aimed compound of formula I (Y is 2-oxo-1,3-dioxolan-4-yl). |
