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Radical Cyclization in Heterocycle Synthesis. 11. A Novel Synthesis of α,β-Disubstituted γ-Lactones via Sulfanyl Radical Addition−Cyclization Using Hydroximates as a Tether
journal contribution
posted on 2000-09-15, 00:00 authored by Okiko Miyata, Atsuko Nishiguchi, Ichiya Ninomiya, Keiichi Aoe, Kimio Okamura, Takeaki NaitoA combination of sulfanyl radical addition−cyclization of dienes connected with hydroximates and
subsequent conversion of the resulting cyclic hydroximate to the lactones provides a novel method
for the construction of α,β-disubstituted γ-lactones. Upon treatment with thiophenol in the presence
of AIBN, dienes connected with hydroximates smoothly underwent sulfanyl radical addition−cyclization to give cyclic cis- and trans-hydroximates. Hydrolysis of cyclic hydroximates gave the
desired cis- and trans-lactones in high yield. This method was successfully applied to the practical
synthesis of (±)-oxo-parabenzlactone.