Abstract: Compounds of the general formula (I) or a pharmaceutically acceptable salt, derivative, prodrug or stereoisomer therefor are provided: wherein the substituent groups defined by R are each independently selected from the group consisting of H, SiR?3, SOR?, SO2X, C(?O)R?, C(?O)OR?, C(?O)NR?, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, aryl, heteroaryl or aralkyl; the group R? is selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, aminoalkyl, aryl, aralkyl and heterocyclic groups; and the group R? is selected from the group consisting of H, OH, OR?, OCOR?, SH, SR?, SOR?, SO2R?, NO2, NH2, NHR?, N(R?)2, NHCOR?, N(COR?)2, NHSO2R?, CN, halogen, C(?O)H, C(?O)R?, CO2H, CO2R?, CH2OR, substituted or unsubstituted alkyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkylidene, substituted or unsubstituted alkynyl, substi

Abstract: Processes are provided for preparing compounds with a fused ring structure of formula (XIV). Such products include ecteinascidins and have a spiroamine-1,4-bridge. The process involving forming a 1,4 bridge using a 1-labile, 10-hydroxy, 18-protected hydroxy, di-6,8-en-5-one fused ring compound. After formation of the 1,4 bridge, C-18 protection is removed before spiroamine introduction.

Abstract: Compounds having a fused ecteinascidin five ring system with a 1,4 bridge having the structure of formula (VIa or VIb) and compounds in which the —NH2 or —OH of the 1,4 bridge is derivatised are disclosed. Such compounds are useful in the treatment of tumours.