Pure Appl. Chem., 2005, Vol. 77, No. 7, pp. 1269-1276
doi: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.
Keywords: 4-(2-naphthyl)bisoxazoline; Asymmetric iodocyclization; chiral Lewis acids; chiral Lewis bases; enantioselective mercuriocyclization.
*An issue of reviews and research papers based on lectures presented at the 15th International Conference on Organic Synthesis (ICOS-15), held in Nagoya, Japan, 1-6 August 2004, on the theme of organic synthesis. Other presentations are published in this issue, pp. 1087-1296.
All articles from the 15th International Conference on Organic Synthesis (ICOS-15), Nagoya, Japan, 1–6 August 2004.