155106-23-3Relevant academic research and scientific papers
New syntheses of (±)-tashiromine and (±)-epitashiromine via enaminone intermediates
Riley, Darren L.,Michael, Joseph P.,De Koning, Charles B.
, p. 2609 - 2613 (2017/01/09)
The syntheses of the naturally occurring indolizidine alkaloid (±)-tashiromine and its unnatural epimer (±)-epitashiromine are demonstrated through the use of enaminone chemistry. The impact of various electron-withdrawing substituents at the C-8 position of the indolizidine core on the preparation of the bicyclic system is described.
Preparation and reductive transformations of vinylogous sulfonamides (β-sulfonyl enamines), and application to the synthesis of indolizidines
Michael, Joseph P.,De Koning, Charles R.,Malefetse, Tshepo J.,Yillah, Ibrahim
, p. 3510 - 3517 (2007/10/03)
Condensation between the methiodide salts of 1-alkylpyrrolidine-2-thiones and ethyl [(4-methylphenyl)sulfonyl]acetate or 1-[(4-methylphenyl)sulfonyl]propan-2-one afforded several 2-{[(4-methylphenyl)sulfonyl]methylene}pyrrolidines in good yield. These β-sulfonyl enamines are sufficiently nucleophilic for cyclisation with internal electrophiles to give sulfone-substituted indolizines, potentially useful scaffolds for alkaloid synthesis. The carbon-carbon double bond in vinylogous sulfonamides was reduced stereoselectively either by catalytic hydrogenation or by treatment with sodium borohydride to yield β-sulfonyl amines. The sulfone group in β-acyl-β-sulfonyl enamines could be removed by hydrogenolysis with sodium amalgam in THF-methanol to give enaminones.
Formal synthesis of two Elaeocarpus alkaloids: elaeocarpine and isoelaeocarpine
Michael, Joseph P.,Parsons, Andrew S.
, p. 65 - 69 (2007/10/02)
1-(3-Acetoxypropyl)pyrrolidine-2-thione 7, prepared by acetylation and thionation of the readily accessible 1-(3-hydroxypropyl)pyrrolidin-2-one 5, undergoes Eschenmoser alkylidenation (sulfide contraction) with two phenacyl bromides to give the vinylogous amides (E)-1-(3-acetoxypropyl)-2-benzoylmethylenepyrrolidine 8 and the corresponding 2-methoxy-6-methylbenzoyl analogue 14.Reduction of the latter with lithium aluminium hydride yields 1-(3-hydroxypropyl)-2-(2-methoxy-6-methylbenzoyl)methylpyrrolidine 12, thereby completing a formal synthesis of the Elaeocarpus alkaloids elaeocarpine 10 and isoelaeocarpine 11.
