The ester 3 is converted into an amide in 4 by reaction with ammonia and the next step to lactam 5 is an iodolactamization with iodine initiated by trimethylsilyltriflate. The amide group is fitted with a BOC protecting group by reaction with Boc anhydride in 6 and the iodine substituent is removed in an  elimination reaction with DBU to the alkene 7.
The ester 3 is transformed into an amide in 4 through reaction with ammonia, followed by iodolactamization with iodine initiated by trimethylsilyltriflate to form lactam 5. The amide group is subsequently protected with a BOC group via reaction with Boc anhydride in 6, and the iodine substituent is eliminated in an elimination reaction with DBU to yield alkene 7.