Enantioselective iodocyclization and mercuriocyclization of γ-hydroxy-<i>cis</i>-alkenes

Kang, Sung Ho; Kang, Suk Youn; Park, Chul Min; Kwon, Hyo Young; Kim, Mihyong

doi:10.1351/pac200577071269

Pure Appl. Chem., 2005, Vol. 77, No. 7, pp. 1269-1276

http://dx.doi.org/10.1351/pac200577071269

Enantioselective iodocyclization and mercuriocyclization of γ-hydroxy-cis-alkenes

Sung Ho Kang, Suk Youn Kang, Chul Min Park, Hyo Young Kwon and Mihyong Kim

Center for Molecular Design and Synthesis, Department of Chemistry, School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea

Abstract: Asymmetric iodocyclization and mercuriocyclization of γ-hydroxy-cis-alkenes have been established. The iodocyclization has been attained with 1.2 equiv of iodine in the presence of the catalyst system prepared from 0.3 equiv of (R,R)-salen−Co(II) complex and 0.75 equiv of NCS to produce 2-substituted tetrahydrofurans with up to 90% ee. The mercuriocyclization has been achieved using 1.2 equiv of Hg(II) complexed with 4-(2-naphthyl)bisoxazoline (1:1 complex) in the presence of 5 equiv of K₂CO₃ and 10 equiv of MeOH to procure 2-substituted tetrahydrofurans with up to 95 % ee.