No, it is not possible to link PNR's since Turkish Airlines uses Troya and Alaska uses one of Galileo or Travelspan ( not sure which one ) as their main GDS provider where PNR's would not be synchronized at all.

In addition, travel agents would not be able to touch PNR's that they haven't issued themselves due to data protection reasons. If you have booked through a travel agent, they could have issued both tickets under the same PNR though.

Plus, even if they were able to use the TCP command, this does not mean that you would be protected in case of IRROPS. TK has the responsibility to take you from Chisinau to San Francisco and AS has the responsibility to take you from San Francisco to Phoenix. They have no obligation to coordinate among each other since they are two separate contracts.

Also, as craigthemif mentioned above, you would need to collect your bags at SFO regardless of anything, this should not be a major issue.