Cyclization by iodine

Iodolactamization y-lactams. y,8-Unsaturated amides can be converted into y-lactams by treatment with trimethylsilyl triflate (triethylamine, DMAP) to give an imidate, which is cyclized by iodine to an iodo-y-lactam in 50-70% yield (equation I). 8-Lactams can be prepared by this methodology, but yields are low because... 

The j8-(3-benzo[6]thienyl)-a-mercaptoacrylic acids (315), prepared by hydrolysis of the corresponding 5-(3-benzo[6]thenylidene)-rhodanine, may be cyclized by iodine in tetrahydrofuran to give the tricyclic compounds (316).648... 

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