| abstract |
Camptothecin analogues where the camptothecin hydroxy lactone is: (i) a beta -hydroxy lactone; or (ii) the corresp. beta -hydroxy acid resulting from ring-opening of the aforementioned lactone; or a (iii) deriv. of the beta -hydroxy acid in (ii) or its one of its salts. Also claimed are new industrial prods. of formula (M) and (A). R1 = lower alkyl, lower alkenyl, lower alkynyl, halo(lower alkyl), lower alkoxy(lower alkyl) or lower alkylthio(lower alkyl); R20 = H or halo; R22 = F, Cl, or lower alkoxy; R23 = prim. hydroxy-protecting gp.; and R18, R19 = H, halo, lower alkyl, lower alkoxy or OH. |