FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2035732212> ?p ?o ?g. }

• W2035732212 endingPage "1263" @default.
• W2035732212 startingPage "1244" @default.
• W2035732212 abstract "Abstract The chiral oxazinone 2 has been developed as a new chiral glycine equivalent for the asymmetric synthesis of mono‐ and disubstituted α‐amino acids. It is derived from the α‐hydroxycarboxylic acid 1 , which serves as a chiral auxiliary, and is easily accessible in enantiomerically pure form by optical resolution of the racemic compound ( RS )‐1 . For alkylation reactions, 2 was deprotonated with s BuLi or phosphazenic base. Subsequent treatment with alkyl halides yielded the monosubstituted compounds 13/14a − c, e, f, ( ent )‐13d, ( ent )‐14d , while a second alkylation step, via the corresponding enolates, provided the disubstituted compounds 17/18a − d . Both alkylation steps proceeded with good yields and excellent diastereoselectivities (up to 99% de ) and even less reactive electrophiles such as isopropyl iodide could be used. The results obtained in this reaction supported the assumption that the enolate of 2 , as well as those of the monosubstituted derivatives of 2 , have less tendency to form the aggregates that hamper alkylation reactions with other systems with higher oxygen content. From the major diastereomers of both the mono‐ and the disubstituted derivatives of 2 the corresponding α‐amino acids 33a − c and 34a − d were obtained in high enantiomeric purity by hydrolytic cleavage of the oxazinone ring, accomplished either in two steps with aqueous TFA and aqueous NaOH or in one with either aqueous NaOH or 3 N HBr. Alkylation of the enolate ions of ( S )‐2 or ( R )‐2 with epichlorohydrins as bifunctional electrophiles provided the hydroxymethylenecyclopropyl derivatives 21 and 22 . Hydrolysis of 21 and 22 afforded the free amino acids 35 and ( ent )‐35 . Reductive amination with aniline after oxidation of 21 and 22 to the corresponding aldehydes 24 and 26 provided the compounds 25 and 27 , whereas Mitsunobu treatment of 21 and 22 with 1‐phenyl‐3‐(trifluoroacetyl)urea ( 28 ) afforded the urea derivatives 29 and 31 . Hydrolysis of these compounds yielded the corresponding 1‐aminocylopropanecarboxylic acid derivatives 36/( ent )‐36 and ( ent )‐37 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)" @default.
• W2035732212 created "2016-06-24" @default.
• W2035732212 creator A5030662404 @default.
• W2035732212 creator A5039007961 @default.
• W2035732212 creator A5046034361 @default.
• W2035732212 creator A5064150950 @default.
• W2035732212 creator A5072939538 @default.
• W2035732212 creator A5084773152 @default.
• W2035732212 date "2003-03-01" @default.
• W2035732212 modified "2023-10-03" @default.
• W2035732212 title "Asymmetric Synthesis with 6‐<i>tert</i>‐Butyl‐5‐methoxy‐6‐methyl‐3,6‐dihydro‐2<i>H</i>‐1,4‐oxazin‐2‐one as a New Chiral Glycine Equivalent: Preparation of Enantiomerically Pure α‐Tertiary and α‐Quaternary α‐Amino Acids" @default.
• W2035732212 cites W1966053101 @default.
• W2035732212 cites W1971522332 @default.
• W2035732212 cites W1978043003 @default.
• W2035732212 cites W1978110394 @default.
• W2035732212 cites W1984764417 @default.
• W2035732212 cites W1985100994 @default.
• W2035732212 cites W1989691273 @default.
• W2035732212 cites W1991187865 @default.
• W2035732212 cites W1995208007 @default.
• W2035732212 cites W1996492288 @default.
• W2035732212 cites W1999494339 @default.
• W2035732212 cites W2001644190 @default.
• W2035732212 cites W2010169156 @default.
• W2035732212 cites W2012182437 @default.
• W2035732212 cites W2020431589 @default.
• W2035732212 cites W2022734870 @default.
• W2035732212 cites W2026333736 @default.
• W2035732212 cites W2028169725 @default.
• W2035732212 cites W2032714364 @default.
• W2035732212 cites W2034870271 @default.
• W2035732212 cites W2043451677 @default.
• W2035732212 cites W2045816666 @default.
• W2035732212 cites W2051090228 @default.
• W2035732212 cites W2054063399 @default.
• W2035732212 cites W2057360183 @default.
• W2035732212 cites W2058963578 @default.
• W2035732212 cites W2069607377 @default.
• W2035732212 cites W2069752545 @default.
• W2035732212 cites W2071625647 @default.
• W2035732212 cites W2074464850 @default.
• W2035732212 cites W2080001577 @default.
• W2035732212 cites W2089605240 @default.
• W2035732212 cites W2120187580 @default.
• W2035732212 cites W2122101131 @default.
• W2035732212 cites W2145776162 @default.
• W2035732212 cites W2152754825 @default.
• W2035732212 cites W2153013038 @default.
• W2035732212 cites W2153647537 @default.
• W2035732212 cites W2169565693 @default.
• W2035732212 cites W2204572609 @default.
• W2035732212 cites W233628489 @default.
• W2035732212 cites W2949171647 @default.
• W2035732212 cites W2949492912 @default.
• W2035732212 cites W2949961695 @default.
• W2035732212 cites W2950424424 @default.
• W2035732212 cites W2950805181 @default.
• W2035732212 cites W2950865887 @default.
• W2035732212 cites W2951297369 @default.
• W2035732212 cites W2951883353 @default.
• W2035732212 cites W2952519784 @default.
• W2035732212 cites W2952581841 @default.
• W2035732212 cites W2952659526 @default.
• W2035732212 cites W2952874250 @default.
• W2035732212 cites W295484251 @default.
• W2035732212 cites W3150954788 @default.
• W2035732212 cites W4211052293 @default.
• W2035732212 cites W4230471326 @default.
• W2035732212 doi "https://doi.org/10.1002/ejoc.200390179" @default.
• W2035732212 hasPublicationYear "2003" @default.
• W2035732212 type Work @default.
• W2035732212 sameAs 2035732212 @default.
• W2035732212 citedByCount "38" @default.
• W2035732212 countsByYear W20357322122013 @default.
• W2035732212 countsByYear W20357322122014 @default.
• W2035732212 countsByYear W20357322122015 @default.
• W2035732212 countsByYear W20357322122016 @default.
• W2035732212 countsByYear W20357322122017 @default.
• W2035732212 countsByYear W20357322122021 @default.
• W2035732212 countsByYear W20357322122022 @default.
• W2035732212 crossrefType "journal-article" @default.
• W2035732212 hasAuthorship W2035732212A5030662404 @default.
• W2035732212 hasAuthorship W2035732212A5039007961 @default.
• W2035732212 hasAuthorship W2035732212A5046034361 @default.
• W2035732212 hasAuthorship W2035732212A5064150950 @default.
• W2035732212 hasAuthorship W2035732212A5072939538 @default.
• W2035732212 hasAuthorship W2035732212A5084773152 @default.
• W2035732212 hasConcept C104264131 @default.
• W2035732212 hasConcept C118629725 @default.
• W2035732212 hasConcept C138716334 @default.
• W2035732212 hasConcept C145148216 @default.
• W2035732212 hasConcept C146686406 @default.
• W2035732212 hasConcept C155647269 @default.
• W2035732212 hasConcept C161790260 @default.
• W2035732212 hasConcept C164361826 @default.
• W2035732212 hasConcept C178790620 @default.
• W2035732212 hasConcept C185592680 @default.
• W2035732212 hasConcept C2779061078 @default.

• next