induction in the iodocarbocyclizationreaction of 4-pentenylmalonate derivatives having a stereogenic center at an allylic or a homoallylic position has been investigated. The iodocarbocyclizationreactions of 3-oxy-4-pentenylmalonate derivatives proceeded with high cis-selectivity through stereoelectronic control of the oxygenated substituent at an allylic position. In the reaction of (S)-2-siloxy-4-pentenylmalonate
A five-step chemoenzymatic synthesis of (−)-(1R,5S)-cyclosarkomycin 2 has been achieved starting from commercial racemic bicycloheptenone 3. The strategy developed involved — as key steps - an enantioselective microbiologically catalyzed Baeyer-Villiger oxidation followed by a chemical regioselective epoxide ring opening.
Diastereoselective iodocarbocyclization of 4-pentenylmalonate derivatives: Application to cyclosarkomycin synthesis
作者:Osamu Kitagawa、Tadashi Inoue、Takeo Taguchi
DOI:10.1016/s0040-4039(00)79965-5
日期:1994.2
The iodocarbocyclization of 4-pentenylmalonate I having a substituent at the 2 or 3 position effectively proceeded by treating I with I-2 and Ti(OtBu)(4) in the presence of CuO. Stereoelectronic effect of the subtituent at allylic position on diastereoselectivity was notable. As an application of the present reaction, the efficient synthesis of cyclosarkomycin 7 was achieved.
LINZ, GUNTER;WEETMAN, JOHN;, HADY A. F. ABDEL;HELMCHEN, GUNTER, TETRAHEDRON LETT., 30,(1989) N1, C. 5599-5602
作者:LINZ, GUNTER、WEETMAN, JOHN、, HADY A. F. ABDEL、HELMCHEN, GUNTER