Asymmetric Desymmetrization of Saturated and Unsaturated meso-1,2-Diols
作者:Hiromichi Fujioka、Yasushi Nagatomi、Naoyuki Kotoku、Hidetoshi Kitagawa、Yasuyuki Kita
DOI:10.1016/s0040-4020(00)00859-0
日期:2000.12
desymmetrization of saturated and unsaturated cyclic and acyclic meso-1,2-diols has been developed from the ene acetals, prepared from the norbornene carboxyaldehyde and meso-1,2-diols. The intramolecular haloetherification of the ene acetals as a key step afforded 8-membered acetals in a stereoselective manner just by the reaction of norbornene olefin even when the ene acetals from unsaturated meso-1,2-diols having
[GRAPHICS]The first total synthesis of mosin B and a diastereomer was accomplished using asymmetric desymmetrization of the sigma -symmetric diol and the Nozaki-Hiyama-Kishi reaction as the key steps. The THF core segment was stereoselectively constructed employing a stereodivergent synthesis starting from a common intermediate, 4-cyclohexene-1,2-diol, based on a desymmetrization strategy. By virtue of these synthetic results, it is suggested that the absolute configuration is 1a.
Synthetic research on cyclitols using C6-chiron, 6-(benzyloxy)-3-cyclohexen-1-ol: A concise and highly diastereoselective synthesis of (−)-gala-quercitol
Transformation of a C-6-chiron, 6-(benzyloxy)-3-cyclohexen-1-ol into polyoxygenated cyclohexanes involving a stereodivergent epoxide rearrangement was investigated. An asymmetric synthesis of (-)gala-quercitol was accomplished via sequential highly diastereoselective epoxidation, base-promoted epoxide rearrangement, and dihydroxylation. (C) 1999 Elsevier Science Ltd. All rights reserved.