| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1347592 | Tetrahedron: Asymmetry | 2013 | 6 Pages |
An asymmetric synthesis of the melatonin receptor agonist Ramelteon 1 has been achieved, which involved a tandem C–H activation–alkylation/Heck reaction and subsequent highly diastereoselective asymmetric Michael addition to generate the corresponding chiral intermediate, which was readily converted into Ramelteon 1 in 19% overall yield in 15 linear steps.
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(E)-Ethyl 3-(5-(1-(S)-((tert-butylsulfinyl)imino)ethyl)-2,3-dihydrobenzofuran-4-yl) acrylateC19H25NO4S[α]D25=-4.1 (c 1.0, CHCl3)Absolute configuration: (E,S)
Ethyl 2-((8S)-6-(((S)-tert-butylsulfinyl)imino)-2,6,7,8-tetrahydro-1H-indeno[5,4-b]furan-8-yl)acetateC19H25NO4S[α]D25=+96.9 (c 1.0, CHCl3)Absolute configuration: (8S,S)
(S)-Ethyl 2-(6-oxo-2,6,7,8-tetrahydro-1H-indeno[5,4-b]furan-8-yl)acetate.C15H16O4[α]D25=-73.5 (c 1.0, CHCl3)ee value: 92%Absolute configuration: (S)
(S)-Ethyl 2-(2,6,7,8-tetrahydro-1H-indeno[5,4-b]furan-8-yl)acetate.C15H18O3[α]D25=-58.9 (c 1.0, CHCl3)Absolute configuration: (S)
(S)-2-(2,6,7,8-Tetrahydro-1H-indeno[5,4-b]furan-8-yl)ethanol.C13H16O2[α]D25=-81.4 (c 1.0, CHCl3)Absolute configuration: (S)
(S)-2-(2,6,7,8-Tetrahydro-1H-indeno[5,4-b]furan-8-yl)ethanamine.C13H17NO3[α]D25=-69.2 (c 1.0, CHCl3)Absolute configuration: (S)
RamelteonC16H21NO2[α]D25=-54.8 (c 1.0, CHCl3)
