If you send litecoins to a bitcoin address that you control, then you will need to export the private keys from your bitcoin wallet and then import those private keys into your litecoin wallet. Then the address will be available to your litecoin wallet so that you can regain access to the litecoins.
If you send litecoins to a bitcoin address that someone else controls, then you will need to hope that the recipient is willing to export the private keys from their bitcoin wallet and then import those private keys into their litecoin wallet. Then the address will be available to their litecoin wallet so that can regain access to the litecoins.
Litecoin and Bitcoin use different blockchains, so it is impossible for litecoins to end up in a Bitcoin wallet, and it is impossible for Bitcoins to go to a Litecoin wallet.
But isn't it impossible to send tx LTC-BTC (or the other way around)? Won't the tx get rejected due to incorrect address format?
I'd imagine this could only work for addresses starting with "3"