Some users of the MiSTer FPGA board have got OS/2 running on the boards 486sx core even though that core is not fully compatible with the i486sx.
The MiSTer is an open source FPGA board design originally intended to allow hardware emulation of Atari ST computers but its open source nature means that there have been a large number of third party cores made available including some PC based emulations.
Source: eComStation Group on Facebook