A Short Synthesis of the Erythrina Skeleton and of (±)-α-Lycorane
作者:Luis D. Miranda、Samir Z. Zard
DOI:10.1021/ol025534e
日期:2002.4.1
[reaction: see text] A new nonchain 5-endo radical cyclization starting with xanthates was exploited in a short synthesis of (+/-)-alpha-lycorane and the erythrina ring system.
Stereocontrolled Access to Enantiopure 7-Substituted <i>cis</i>- and <i>trans</i>-Octahydroindoles
作者:Elena Ghirardi、Rosa Griera、Miriam Piccichè、Elies Molins、Israel Fernández、Joan Bosch、Mercedes Amat
DOI:10.1021/acs.orglett.6b02861
日期:2016.11.18
afforded tricyclic oxazoloindolone lactams, from which straightforward procedures for the stereocontrolled formation of enantiopure 7-substituted octahydroindoles with a variety of stereochemical patterns have been developed. The methodology has been successfully applied to the synthesis of (+)-α-lycorane.
cyclohexanecarboxylic acid (10), both of which were prepared by the Diels-Alder reaction of 3,4-methylenedioxy - ω - nitrostyrene with butadiene and the Robinsonannelation of 3,4-methyl- enedioxy - phenylpyruvic acid (9) with methyl vinyl ketone, respectively, 14a was converted into (±)Δ2-α-lycoren-7-one (22b), which has been transformed into (±)-lycorine (1) by Torssell
Total synthesis of (±)-α-lycorane and 4,5-dehydroanhydrolycorine
作者:James H. Rigby、Mary E. Mateo
DOI:10.1016/0040-4020(96)00605-9
日期:1996.8
The total syntheses of (±)-α-lycorane and dehydroanhydrolycorine are described. The key intermediate in both approaches is the hydroindolone 5, prepared from the [1+4] cycloaddition reaction of 1-isocyanatocyclohexene and cyclohexyl isocyanide. Alkylation of 5 with arylbromide 6 afforded 7. Hydrolysis of enamide 7 followed by reduction of the resultant enol yielded 10 as a single diastereomer. Radical-based
Asymmetric Catalytic Conjugate Addition of Acetaldehyde to Nitrodienynes/Nitroenynes: Applications to the Syntheses of (+)-α-Lycorane and Chiral β-Alkynyl Acids
The catalytic enantioselective conjugateaddition of acetaldehyde to polyconjugated substrates, nitrodienynes and nitroenynes, has been accomplished using organocatalysis. Various functionalized 1,3-enynes and propargylic compounds were obtained in moderate to good yields with high enantioselectivity. The synthetic utilities of the conjugateaddition reactions have been highlighted in the concise total