Crouton allows installing Ubuntu or Debian in a chroot environment on any Chromebook model, without removing Chrome OS.

You can read more about Crouton and installing Ubuntu on a Chromebook using it in an article I posted a while back: How To Install Ubuntu Linux On Any Chromebook Model Without Replacing Chrome OS (Crouton)

Crouton used to have a target which allowed easy Cinnamon installation, but that’s no longer available. Installing Cinnamon desktop on a Chromebook using Crouton is still possible, and this article guides you through this process. 

Cinnamon is a desktop environment that’s derived from Gnome 3 but using a traditional desktop layout, being the main desktop environment of the Linux Mint distribution. Since Crouton doesn’t support Linux Mint, Ubuntu 18.04 (Bionic Beaver) will be used as the Linux distribution on top of which we’ll install Cinnamon desktop.

Read more at LinuxUprising