To answer several instances of the same question at once: Regardless of whether you think "pay me $COUPON every 6 months until date D when you pay me $PRINCPIA

To answer several instances of the same question at once: Regardless of whether you think "pay me $COUPON every 6 months until date D when you pay me $PRINCPIAL" might be considered "synthetic" surely you must all admit it's far less synthetic than "Pay me $X if and when CORPORATION defaults"!