Asymmetric Synthesis of Isoquinoline Alkaloids: (R)- and (S)-2-Ethoxycarbonyl-1-Formyl-6, 7-Dimethoxy-1,2,3,4-Tetrahydroisoquinoline as Versatile Precursors
摘要:
AbstractA method is described for the preparation of (R)‐ and (S)‐2‐ethoxycarbonyl‐1‐formyl‐6,7‐dimethoxy‐1,2,3,4‐tetrahydroisoquinoline involving a Swerntype oxidation of (R)‐ and (S)‐2‐ethoxycarbonyl‐1‐hydroxymethyl‐6, 7‐dimethoxy‐1,2,3,4‐tetrahydroisoquinoline {(R)‐ and (S)‐2‐(ethoxycarbonyl)calycotomine}. The utility of these aldehydes in asymmetric synthesis of isoquinoline alkaloids has been demonstrated by their conversion into (S)‐ and (R)‐xylopinine, respectively; also, the (R)‐aldehyde has been employed for the synthesis of (8S,14S)‐coralydine.
An Acyl-Claisen Approach to Tetrasubstituted Tetrahydrofuran Lignans: Synthesis of Fragransin A2, Talaumidin, and Lignan Analogues
作者:David Barker、Claire Rye
DOI:10.1055/s-0029-1218363
日期:2009.12
A simple and stereocontrolled synthesis of racemic 2,3,4,5-tetrasubstituted tetrahydrofurans was achieved from acyl-Claisen derived syn-disubstituted amides.
Redox deracemization of α-substituted 1,3-dihydroisobenzofurans
作者:Xiaohan Chen、Ran Zhao、Ziqiang Liu、Shutao Sun、Yingang Ma、Qingyun Liu、Xia Sun、Lei Liu
DOI:10.1016/j.cclet.2021.02.021
日期:2021.7
However, catalytic asymmetric approaches have been rarely developed. Here, a redox deracemization technology is adopted to address the catalytic asymmetric synthesis. A broad range of α-aryl substituted 1,3-dihydroisobenzofurans are effectively deracemized in high efficiency with excellent ee. α-Alkynyl substituted ethers were also compatible with the deracemization technology.
Enantioselective Transfer Hydrogenation of Oxocarbenium Ions Enables Asymmetric Access to α-Substituted 1,3-Dihydroisobenzofurans
作者:Xigong Liu、Lei Liu、Likai Zhou、Kuiyong Jia
DOI:10.1055/a-1643-8526
日期:2022.1
Reported here is an efficient enantioselective transfer hydrogenation of cyclic oxocarbenium ions generated in situ through collapse of the corresponding acetal substrates. The asymmetric approach provides straightforwardaccess to a variety of chiral α-aryl substituted 1,3-dihydroisobenzofurans in high yields with excellent enantioselectivities. α-Alkynyl substituted 1,3-dihydroisobenzofurans were
作者:Charles B. de Koning、Joseph P. Michael、Amanda L. Rousseau
DOI:10.1016/s0040-4039(96)02435-5
日期:1997.2
Irradiation of 2-allylated acylbenzenes in DMF in the presence of potassium tert-butoxide constitutes a novel synthesis of substitutednaphthalenes, including arylnaphthalenes. Typical examples include the conversions (1) → (2), (8) → (11) and (15 → (16).
O-Methylpallidinine, a recently isolated morphinan alkaloid, has been synthesized in 16 steps from 1,4-cyclohexanedione and 3-bromoveratrole. The synthesis employs a new method for preparing the morphinan skeleton in which diazomethane is added to an aryloctahydroquinolinium salt.