Google’s Eric Schmidt, now in the news at Google, is one of the few people I can think of who went from theoretical researcher to billionaire CEO without really being an entrepreneur. I knew of him in the 1980s when I worked at Bell Labs because of the program lex that he co-authored, a beautiful piece of work that was part of the UNIX toolset and allowed you to create lexical analyzers without writing them yourself. You specified the regular expression you wanted to search for, it generated the program to do it. A program that wrote programs, classic UNIX stuff. From there he went to Sun, Novell, etc, but always as far as I recall in technical roles. Until Google.
A nominally similar person he brings to mind is Howard Sosin, who started out as a business school professor at Columbia, and co-wrote a paper that defined and valued one of the first really exotic options, the lookback. From there he went on to found AIG Financial Products. The rest, as they say, is