Originally Posted by CAlex

Can you advise why you want to fly in C to ADB, especially LH? Economy ticket prices are ~225 EUR/pax with TK or LH. TK flies both to BSL and ZRH, and then they have hourly flights from IST to ADB.

I would just book the cheap TK tickets, be happy that you will have a nice flight to IST (great Y product), then access to the lounge if you need to and if you have time, great way to fly to ADB and earn miles, not spend miles...