Reductive radical cyclization of cyclic γ-cyanoketones promoted by samarium(II) iodide without photoirradiation

Reaction of cyclic γ-cyanoketones with 3 equiv. of SmI2 in the presence of t-BuOH as a proton source in HMPA–THF without photoirradiation gave the desired α-hydroxycycloalkanones along with overreduced ketones after hydrolysis. In the absence of t-BuOH, the formation of the overreduced ketones was depressed and the yields of the α-hydroxyketones increased, while the reaction proceeded slowly.