http://winscp.net/eng/docs/commandline
めも
For security reasons, when protocol (sftp://, ftp:// or scp://) is provided on command line (possible execution from web browser/Windows Explorer), all command-like parameters that cause any automatic action are ignored, including /defaults, /log, /script and /command.
/synchronizeが自動実行されないのは仕様のようだ/command "synchronize 〜"で解決
