Studies Directed toward the Synthesis of Aspidophytine: Construction of Its Perhydroquinoline Core
JOURNAL OF ORGANIC CHEMISTRY, cilt.81, sa.21, ss.10454-10462, 2016 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 81 Sayı: 21
- Basım Tarihi: 2016
- Doi Numarası: 10.1021/acs.joc.6b01574
- Dergi Adı: JOURNAL OF ORGANIC CHEMISTRY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Index Chemicus (IC)
- Sayfa Sayıları: ss.10454-10462
- Orta Doğu Teknik Üniversitesi Adresli: Hayır
Özet
We have developed an efficient route for the synthesis of the perhydroquinoline core of the indole alkaloid aspidophytine (2), starting from commercially available and inexpensive 3-acetylpyridine. This densely functionalized perhydroquinoline core displays four contiguous stereocenters including an all-carbon quaternary center. The synthetic sequence features a highly effective Diels-Alder reaction using a carbamate-substituted siloxy diene accompanied by a spontaneous intramolecular substitution of the newly formed 3 degrees-alkyl bromide with a carbamate group. The installation of the electron-rich aniline moiety was accomplished via a TBSOTf-mediated intramolecular aza-Michael reaction, and the relative stereochemistry of the aza-Michael product (30) was confirmed by X-ray crystallographic analysis. Among the useful transformations that were developed through this study is a highly enantioselective Diels-Alder reaction of a versatile cyclic carbamate siloxy diene.