A HIGHLY CONCISE SYNTHESIS OF LAVENDAMYCIN METHYL-ESTER

Lavendamycin methyl ester (2), an antitumor antibiotic, was synthesize d by a practical and short route in an excellent overall yield of 33% from known starting materials. Pictet-Spengler condensation of 7-aceta mido-2-formylquinoline-5,8-dione (4) with the methyl ester of (2RS,3SR )-beta-methyltryptophan (5) followed by hydrolysis afforded 2. Aldehyd e 4 was prepared by the oxidation of 7-acetamido-2-methylquinoline-5,8 -dione (9). Dione 9 was obtained via the Diels-Alder condensation of t he novel tyldimethylsilyl)oxy]-2-methyl-1-aza-1,3-butadiene (7) with 2 -acetamido-6-bromobenzene-1,4-dione (8).