| 摘要 |
<p>PURPOSE:To obtain the derivative useful as an antimicrobial agent having excellent intracorporeal kinetics, having antimicrobial action, especially protecting action on infection, comprising a macrolactone compound having a lower alkyl group at the 2-position of mycamynosyltynololide. CONSTITUTION:A compound of formula I [R<3> is OH or mysinosyl; R<4> is H or OH; R<a> is (protected) OH; A is (protected) aldehyde; B is (protected) carbonyl] [e.g 3,4'-dideoxy-23-O-t-butyldimethylsilylmycamynosyltynololide-9,10-bis(e thylene acetal)] is treated with n-butyllithium in THF in the presence of diisopropylamine at -70 deg.C and alkylated with methyl iodide at -40 deg.C for 3 hours. Then the reaction product is treated with hydrochloric acid to remove the protecting group and purified by silica gel column chromatography to obtain a 2-alkyltyrosine derivative of formula II (R<1> is lower alkyl; R<2> is H or formyl; X is oxygen, etc.).</p> |
