If Synaptic list Gnome as an available package, then it's reasonable to expect Synaptic to resolve the dependencies, because that's what Synaptic does.
For diagnostic purposes, I'd suggest that you try to install the package from the command line with
apt or apt-get, then note what error messages get thrown to the terminal window, then post the ones that seem relevant here.
Code:
sudo apt install [package name]
Please surround any terminal output with "code" tags which become available when you click the "Go Advanced" button beneath the compose post window.
