Transfer from Bitcoin Core to Electrum expired before full synchronization. Where are the bitcoins?
If you broadcasted the transaction, it will appear on the other end, eventually.

I suggest you to first go to https://blockchain.info/ and look-up your electrum address or the transaction ID. There, you should see if the transaction is still unconfirmed or has already been confirmed.
In both cases, you should see it in electrum. If you don't see it, try exiting electrum, deleting blockchain_headers file in %appdata%\Electrum, and running it again. This will force it to re-scan everything.