First, welcome captjohn!!

When I have used RSSC air from SFO, they have put me on Lufthansa (I request Star Alliance as I am United Mileage Plus). I would imagine they would put you on United to the mainland, then the United or Lufthansa flight leaving SFO at 2:30pm to Frankfurt, then Lufthansa to IST arriving local time about 5:30ish. I believe there is about a 3.5 hour layover in Frankfurt.

OOOPS! I just realized you couldn't get here in time to make the 2:30 flight! Now I don't know! Would they put you up on the West Coast or put you on a night flight to London or something with onward connections?? Are you going to get the business class upgrade??

I'm not much help at all, sorry...Whatever they do you are in for a looong haul!