Synchronizing won't do for such a complex task. You need to use scripting.

These examples may help you:
https://winscp.net/eng/docs/script_download_timestamped_filename
https://winscp.net/eng/docs/script_checking_file_existence

Hi,

i need to automatically download backup files from a server to a local directory. What will be the best approach to get this achieved (synchronize, scripting, etc.). Following you can see the server structure and how i want it to be placed on the client.

Server

backup
-- db1
---- db1_2011-08-01.bak
---- db1_2011-08-02.bak
-- db2
---- db2_2011-08-01.bak
---- db2_2011-08-02.bak
-- db3
---- ...
-- ...

I want this to be downloaded to the client in a structure like this

backup
-- 2011-08-01
---- db1_2011-08-01.bak
---- db2_2011-08-01.bak
-- 2011-08-02
---- db1_2011-08-02.bak
---- db2_2011-08-02.bak