Asymmetric Synthesis and Reactions of cis-N-(p-Toluenesulfinyl)aziridine-2-carboxylic Acids
摘要:
cis-Aziridine-2-carboxylic acids, 2, precursors of the difficult to prepare syn-beta-hydroxy-alpha-amino acid structural unit, are prepared in high diastereomeric purity by a Darzens-type reaction of the lithium enolate of methyl bromoacetate with enantiopure sulfinimines 1.
Asymmetric Synthesis and Reactions of cis-N-(p-Toluenesulfinyl)aziridine-2-carboxylic Acids
摘要:
cis-Aziridine-2-carboxylic acids, 2, precursors of the difficult to prepare syn-beta-hydroxy-alpha-amino acid structural unit, are prepared in high diastereomeric purity by a Darzens-type reaction of the lithium enolate of methyl bromoacetate with enantiopure sulfinimines 1.
Asymmetric Synthesis of 2<i>H</i>-Azirine 2-Carboxylate Esters
作者:Franklin A. Davis、Hu Liu、Chang-Hsing Liang、G. Venkat Reddy、Yulian Zhang、Tianan Fang、Donald D. Titus
DOI:10.1021/jo991389f
日期:1999.11.1
sulfenic acid (RSOH) from nonracemic N-sulfinylaziridine 2-carboxylate esters (4). Optimum yields were obtained when the aziridine was treated with TMSCl at -95 degrees C followed by LDA, which was attributed to the improved leaving group ability of an silicon-oxonium species. By using this new methodology the first asymmetric syntheses of the marine cytotoxic antibiotics (R)-(-)- and (S)-(+)-dysidazirine
Aziridine compounds, methods of preparation and reactions thereof
申请人:Drexel University
公开号:US05789599A1
公开(公告)日:1998-08-04
Novel N-sulfinyl-2-carboxyaziridine compounds and novel N-hydrogen-2-hydroxymethylaziridine compounds are provided. The asymmetric synthesis of N-sulfinylaziridines is readily accomplished in high diastereomeric purity and good yield by the Darzens-type reaction of the metal enolate of an .alpha.-haloester and an enantiopure sulfinimine. Ring-opening of these aziridines affords .alpha.-amino acids and the otherwise difficult to prepare syn-.beta.-hydroxy-.alpha.-amino acids, both key structural units found in many bioactive materials. The N-sulfinyl radical may be selectively removed from the novel aziridine compounds by treatment with acid or base. Alternatively, the N-sulfinyl radical may be oxidized to provide the corresponding N-sulfonyl-aziridine, or reduced to form the corresponding 1H-2-hydroxymethylaziridine, either of which may subsequently be ring-opened to provide precursors to bioactive compounds.
Asymmetric Synthesis of β-Substituted α-Amino Acids Using 2<i>H</i>-Azirine-2-carboxylate Esters. Synthesis of 3,3-Disubstituted Aziridine-2-carboxylate Esters
作者:Franklin A. Davis、Chang-Hsing Liang、Hu Liu
DOI:10.1021/jo9702610
日期:1997.6.13
Asymmetric Synthesis using Sulfinimines (Thiooxime S-Oxides)
作者:Franklin A. Davis、Padma S. Portonovo、Rajarathnam E. Reddy、G. Venkat Reddy、Ping Zhou
DOI:10.1080/10426509708545525
日期:1997.1.1
Asymmetric Synthesis of 2H-Azirines: First Enantioselective Synthesis of the Cytotoxic Antibiotic (R)-(-)-Dysidazirine