| 摘要 |
<p>The invention refers to a process for the preparation of compounds of formula ( I ) <CHEM> wherein R1 is an aryl or heteroaryl group; R2 is hydrogen, arylcarbonyl, heteroarylcarbonyl or C1-C6 alkoxycarbonyl; R3 is hydrogen or acetyl; the process comprising reacting a compound of formula (II) <CHEM> wherein R1 is as defined above, the symbol --- represents a single or a double bond, R7 is C1-C6 alkoxycarbonyl, arylcarbonyl or heteroarylcarbonyl, each of R4 and R5 independently is hydrogen, C1-C6 alkyl, C1-C3 alkoxy, aryl or heteroaryl; and R6 is C1-C6 alkyl, aryl or heteroaryl, provided that when the symbol --- is a double bond, R7 and R4 do not exist and R5 is aryl or heteroaryl, with a compound of formula (III) <CHEM> wherein each of R8 and R9 independently is a hydroxy protecting group in the presence of a condensing agent so obtaining a compound of formula (IV) <CHEM> wherein R1, R4, R5, R7, R8 and R9, and the symbol --- are as defined above, provided that when --- is a double bond R7 and R4 do not exist and R5 is aryl or heteroaryl, and deprotecting the compound of formula (IV) under such condition so as to produce the compound of formula (I), as defined above, and optionally transforming a compound of formula (I) into another compound of formula (I). The compounds of formula (II) are also claimed. The compounds of formula (I) are antitumoral compounds.</p> |
