I am not aware of a pre-made crosswalk available between OCC1990 and the SOC classification scheme. As Joe pointed out in 2014, however, you may be able to generate one yourself. First, create an extract with a recent year’s (since 2011) ASEC sample with both OCC and OCC1990 variables included. Using that extract, keep one case for every unique OCC1990 code. This will give you a crosswalk between OCC and OCC1990. You can then use Appendix B of the appropriate year’s ASEC codebook to create a crosswalk between OCC and the 2010 SOC codes. Then, using OCC as a bridge, you can create the crosswalk between OCC1990 and SOC 2010.
It sounds like you are using IPUMS CPS data, but in the event you are using IPUMS USA data, this IPUMS USA page has a crosswalk between 2010 OCC codes and SOC codes which may be helpful.
I hope this helps.