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 undergoes conversion into an amide through interaction with ammonia, followed by a process of iodolactamization using iodine as a catalyst to form lactam 5. The amide is then modified by the attachment of a BOC protective group via reaction with Boc anhydride in step 6, and the iodine substituent is removed through an elimination reaction with DBU to yield alkene 7.