Total Synthesis of (±)-α- and β-Lycoranes by Sequential Chemoselective Conjugate Addition−Stereoselective Nitro-Michael Cyclization of an ω-Nitro-α,β,ψ,ω-unsaturated Ester

• Published in: Organic letters Vol. 5; no. 7; pp. 1123 - 1126
• Main Authors: Yasuhara, Tomohisa, Nishimura, Katsumi, Yamashita, Mitsuaki, Fukuyama, Naoshi, Yamada, Ken-ichi, Muraoka, Osamu, Tomioka, Kiyoshi
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 03.04.2003; Amer Chemical Soc
• Subjects: Alkaloids - chemical synthesis; Alkaloids - chemistry; Amaryllidaceae Alkaloids; Chemistry; Chemistry, Organic; Cyclization; Esters - chemistry; Molecular Structure; Nitrogen - chemistry; Physical Sciences; Science & Technology; Stereoisomerism; ALDOL TANDEM CYCLIZATION; OMEGA-OXO-ALPHA,BETA-UNSATURATED ESTERS; ASYMMETRIC-SYNTHESIS; ENANTIOSELECTIVE SYNTHESIS; NITROALKANES; DIALKYLZINC REAGENTS; 1,4-ADDITION; CARBON BOND FORMATIONS; ORGANOLITHIUM; LYCORINE

An ω-nitro-α,β,ψ,ω-unsaturated ester underwent a chemoselective conjugate addition of a nitroolefin moiety with aryllithium to produce a ψ-aryl-ω-nitro-α,β-unsaturated ester, which was then stereoselectively cyclized by intramolecular nitro-Michael reaction giving a functionalized cyclohexane applic...