| 摘要 |
<p>PURPOSE:To obtain a lactone useful as an intermediate for an antibacterial agent industrially advantageously, by oxidizing a ketone which is prepared by protecting a ketone of a ketoester, reducing the ester, followed by removing the ketone-protecting group. CONSTITUTION:A ketone of a ketoester shown by the formulaI(R<1> is alkyl; R<2> is lower alkyl) is protected (a ketal such as ethylene ketal, etc. may be cited as the protecting group), the ester is reduced, and the ketone-protecting group is removed, to give a compound shown by the formula II (one having 2-10C alkyl, is a novel compound), which is oxidized to give a lactone shown by the formula III. Lithium alluminum hydride, etc. is used as a reducing agent in the reduction, and Baeyer-Villiger reaction wherein the ketone is oxidized with H2O2, etc. to give the ester is applied in the oxidation. The compound shown by the formula III is alkylated so that a 2-alkyl-5-alkyl-5-(hydroxymethyl)-5-pentanolide can be prepared.</p> |
