142796-65-4

Upstream product

• 142764-74-7 (6S)-4-(1,3-dithiolan-4-yl)indolizidin-9-one 
• 287974-12-3 (S)-1,2,8,8a-tetrahydroindolizin-3(5H)-one 
• 342007-92-5 (R)-5-Hydroxy-hexahydro-indolizin-3-one 
• 82259-09-4 (5S)-(+)-5-(1-Prop-2-enyl)-2-pyrrolidinone 
• 118794-69-7 6-[(tert-butyldimethylsilyl)oxy]hexanal 
• 142764-58-7 N-<(S)-1-(benzyloxycarbonyl)-2-methylpropyl>-(6S)-6-<2-(ethoxycarbonyl)ethyl>-2,3-didehydropiperidin-4-one 
• 132599-88-3 (6S)-6-<2-(ethoxycarbonyl)ethyl>-2,3-didehydropiperidin-4-one 
• 142764-72-5 (6S)-indolizidin-4,9-dione 
• 142764-71-4 (6S)-2,3-didehydroindolizidine-4,9-dione 
• 287974-07-6 (S)-5-Allyl-1-((S)-2-hydroxy-1-phenyl-ethyl)-pyrrolidin-2-one 
• 287974-10-1 (S)-1,5-diallylpyrrolidin-2-one 
• 342007-90-3 (R)-5-Pent-4-enyl-pyrrolidin-2-one 
• 342007-93-6 4-((R)-5-Oxo-pyrrolidin-2-yl)-butyraldehyde 
• 288387-56-4 (5S)-5-[(p-toluenesulfonyl)methyl]-2-pyrrolidinone 

Relevant academic research and scientific papers

Synthesis of indolizidine, pyrrolizidine and quinolizidine ring systems by proline-catalyzed sequential α-amination and HWE olefination of an aldehyde

A general procedure for the synthesis of azabicyclic ring systems viz. indolizidine, pyrrolizidine and quinolizidine has been developed utilizing proline-catalyzed sequential α-amination and Horner-Wadsworth-Emmons (HWE) olefination of an aldehyde as the key step. This method can be further extended to the synthesis of various biologically active natural products containing azabicyclic ring systems.

SmI2-mediated hetero-coupling reaction of lactams with aldehydes; synthesis of indolizidine alkaloids, (-)-δ-coniceine, (+)-5-epiindolizidine 167B and (+)-lentiginosine

Treatment of alicyclic and aromatic lactams with several aldehydes in the presence of samarium(II) diiodide was found to undergo a novel nitrogen-carbon (hetero) coupling reaction to generate N-α-hydroxyalkylated lactams in high yield. The chiral lactams with an aldehyde-side chain incorporating the L-pyroglutamic acid- or L-tartaric acid-derived skeleton also reacted intramolecularly under the same conditions to afford the corresponding bicyclic coupling products, which were further applied to the convenient syntheses of (-)-δ-coniceine, (+)-5-epiindolizidine 167B and (+)-lentiginosine, respectively.

Convergent asymmetric synthesis of indolizidines from (S)-5-(tosylmethyl)-2-pyrrolidinone: Synthesis of (-)-δ-coniceine

The enantiomerically pure (S)-5-(tosylmethyl)-2-pyrrolidinone 2, prepared from commercially available (S)-pyroglutaminol, is dialkylated at the nitrogen atom and the α-sulfonyl position using several dielectrophiles using sodium hydride as the base to diastereoselectively afford indolizidine derivatives 5 and the less common hexahydropyrrolo[1,2-a]azepin-3-one 6 in moderate to good yield. This domino process has been applied to the synthesis of (-)-δ-coniceine.

Concise synthesis of indolizidines: Total synthesis of (-)-coniceine

The Ti-mediated allylsilane addition to bicyclic lactams occurs with high stereoselectivity and combined with a ring closure metathesis provides the title compounds in high ee.

Asymmetric Tandem Mannich-Michael Reactions of Amino Acid Ester Imines with Danishefsky's Diene

Imines 1 derived from aromatic, aliphatic, and functionalized aldehydes and various amino acid esters react with Danishefsky's diene under Lewis acid catalysis via a tandem Mannich-Michael mechanism to give cyclic 6-substituted 2,3-didehydro-4-piperidinones in good to high yields and with diastereomeric ratios reaching from 92:8 up to 97:3.The chiral auxiliary is removed by conversion of the α C atom of the amino acid into an acetalic center, employing a Curtius reaction as the key step.For the elucidation of the absolute configuration, the alkaloids (S)-coniine and (R)-δ-coniceine are synthesized from the enaminones 5i and 5r.