| 摘要 |
<p>A process for the preparation of compounds of formula (I), wherein R1 represents hydrogen, C¿1-4? alkyl, CHR?3CONHR4 or CHR3COOR4¿ in which R?3 and R4¿ each independently represent hydrogen or C¿1-4?alkyl; R?2¿ represents hydrogen or C¿1-5? alkyl; and n is an integer 2, 3 or 4; which process comprises cyclising a compound of formula (II), wherein R?2¿ and n are as defined in relation to formula (I); R5 represents hydrogen or a group COOR7 wherein R7 is a C¿1-4? alkyl group or a benzyl group; and R?6¿ represents a hydroxy group or a group OR8 wherein R8 represents C¿1-6? alkyl or a benzyl group; and thereafter, as necessary, carrying out one more of the following steps: i) removing any protecting group; and ii) converting a compound of formula (I) into another compound of formula (I).</p> |
