Install Oracle VirtualBox and install Windows XP 32 bit.
Mount the Guest Additions image and install them.
Create an ISO from the Civ 3 installation CD using
hdiutil makehybrid -iso -joliet -o civ3.iso /Volumes/CIV3/
Mount the ISO on VirtualBox and install the game.
Download and install the following patch to bring the installation up to 1.29f. See this site.
Download the No CD patch from the PC Gamer site. Specifically, I needed this file: Civilization 3 PC Games Patch mit Conquest v1.29f (d).zip provided below.
Lastly with VirtualBox running full screen Civ 3 doesn’t fill the screen. Edit Civilization3.ini from C:\Program Files\Infogrames Interactive\Civilization III and add KeepRes=1
[Civilizaion III]
KeepRes=1