I\'m not asking for the option to automatically follow the current file in the solution explorer. This has been answered in this question a
On my keyboard I had to press:
Ctrl + ` + S
Do note that the sign in the middle is the key just left of the backspace.
Using Visual Studio 2015.
In Visual Studio 2010/2012 you can use this extension (link). It adds option to sync on Solution Explorer toolbar and code context menu.
If I got your question right, you can go to Tools -> Options -> Projects and Solutions -> General and check the "Track Active Item in Solution Explorer" option.
In Visual Studio 2015, with ReSharper, I am able to press Shift + Alt + L to highlight the current file being edited in Solution Explorer.