Question: So I have a very nice 27" 5K iMac, late 2014 model.  

It runs Big Sur, but it doesn't get the Monterey upgrade, because it is 1 generation too old.

[I believe I can get Monterey to work using OCLP](https://github.com/dortania/Opencore-Legacy-Patcher/releases) on this hardware, but I rather don't want to mess with that as that would require a full re-install, for which I have no time. (A lot of home-brew/custom software that would need to be setup fresh.)

So I wonder if I can run Monterey in a VM instead, even though the underlying hardware is officially not supported.  

(I've got 24 GB RAM to play with. Plenty for a VM.)

I can just give it a try off course, but Monterey is a big download and I have very limited bandwidth at the moment, that is also needed for other stuff during the day.  

I rather not download the whole thing over several nights to find that it doesn't work.

Can anyone confirm whether this would work or not?

Answer: 
I have macOS Monterey version 12.1 installed on a VMware Fusion Player virtual machine on a iMac (21.5-inch, Late 2013) host. The iMac is running macOS Catalina version 10.15.7 from a 5 Gb/s USB port. The USB drive is a 500 GB Samsung T7 SSD. The VMware Fusion Player is the free for personal use version 12.1.2.

I created a Monterey installer drive by using a Big Sur virtual machine. I following Apple's instructions: [How to create a bootable installer for macOS](https://support.apple.com/en-us/HT201372). Instead of using a USB flash drive, I created and used a second SATA drive for the installer.

The virtual machine has 2 processor cores and 4096 MB of memory out of the 4 processor cores and 16 GB of memory installed in the iMac. This is a custom virtual machine where macOS 11.0 was selected as the operating system.
Self answer as I now had the opportunity to try.

I tried it on 2 different Macs (iMac late 2014 and a 2013 MacBook Pro) with Parallels, VMWare Fusion and VirtualBox with the same disappointing results.

It won't work properly. In all cases the installer or the first stage of the setup after the base install will throw a kernel-panic.

In Parallels and VirtualBox it would crash early after only 2 or 3 click-through screens in the beginning of the installation.  

VMWare Fusion at least got to the part when it starts copying files to the harddisk and in one case to the first screen after that, but eventually crashed as well.  

I tried each a coupl eof times. The exact moment of the crash varies a bit, but eventually it will crash.

With all 3 virtualization platforms I was able to make a virtual Big Sur and that worked fine. But these I couldn't upgrade to Monterrey either. With the same "unsupported" messages as I got on the real hardware.

My only option right now seems to try OCLP on a virtual machine (no idea if that would work) or spend a lot of money on a new Mac (which isn't in the budget for this year).