| 摘要 |
<p>NEW MATERIAL:A clavulone derivative expressed by formula I [R<1> and R<2> are H or lower alkanoyl; X is -CH2OR<3> (R<3> is H or lower alkanoyl) or formula II (R<4> and R<5> are H, lower alkyl or lower alkoxycarbonyl)]. EXAMPLE:A compound expressed by formula III. USE:The above-mentioned dervative has antitumor action and is useful as an antitumor agent. PREPARATION:A compound expressed by formula IV is e.g. reduced with sodium borohydride in the presence of cerium chloride and then a protecting group is introduced into the reaction product to afford a compound expressed by formula V, which is then reduced in the next process and acetylated and successively a protecting group is removed to give a compound expressed by formula VI. The resultant alcohol expressed by formula VI is oxidized using an oxidizing agent, preferably pyridinium chlorochromate to provide the compound expressed by formula VII (Ac is acetyl) among formula I.</p> |
