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Volumn 22, Issue , 2000, Pages 33-58

Asymmetric synthesis based on enolate chemistry: β-lactam synthesis and memory of chirality

Author keywords

lactam; Amino acid; Asymmetric synthesis; Dynamic chirality; Enolate; Memory of chirality; Reagent control

Indexed keywords


EID: 0034560211     PISSN: 09156151     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Review
Times cited : (7)

References (49)
  • 26
    • 0039938517 scopus 로고    scopus 로고
    • note
    • A base like DBU, DBN, or sodium hydroxide (room temperature) failed to effect noticeable epimerization at C(3) and/or C(4) of 8.
  • 27
    • 0023919595 scopus 로고
    • Conversion of central chirality into axial chirality has been reported in NAD-NADH model studies, see: A. Ohno, M. Ogawa and S. Oka: Tetrahedron Lett. 29 3079-3082 (1988).
    • (1988) Tetrahedron Lett. , vol.29 , pp. 3079-3082
    • Ohno, A.1    Ogawa, M.2    Oka, S.3
  • 28
    • 0030917481 scopus 로고    scopus 로고
    • Asymmetric synthesis using non-biaryl atropisomers has been reviewed, see: J. Clayden: Angew Chem. Int. Ed. Engl. 36 949-951 (1997).
    • (1997) Angew Chem. Int. Ed. Engl. , vol.36 , pp. 949-951
    • Clayden, J.1
  • 32
    • 0030955088 scopus 로고    scopus 로고
    • Recent progress in asymmetric synthesis of α,α-disubstituted α-amino acids has been reviewed, see: T. Wirth: Angew. Chem. Int. Ed. Engl. 36 225-227 (1997).
    • (1997) Angew. Chem. Int. Ed. Engl. , vol.36 , pp. 225-227
    • Wirth, T.1
  • 33
    • 0039938514 scopus 로고    scopus 로고
    • note
    • 2S, 2) 1 M NaOH, 3) 47% aq. HBr.
  • 34
    • 0041125393 scopus 로고    scopus 로고
    • note
    • 39 and 40 were separately isolated in 56% and 27% yields, respectively. Each of them exists as a mixture of N-Boc E/Z isomers (4:1 for 39 and 5:1 for 40).
  • 35
    • 0041125392 scopus 로고    scopus 로고
    • note
    • ≠ of the restricted bond rotation is nearly zero.
  • 36
    • 0040531401 scopus 로고    scopus 로고
    • The absolute configuration of E is shown provisionally
    • The absolute configuration of E is shown provisionally.
  • 37
    • 0040531400 scopus 로고    scopus 로고
    • note
    • The Z- and E-enolate intermediates should afford α-methylated products of the same absolute configuration, since the 2:1 geometric mixture of enolates gave the product of 81% ee in 96% yield (Table VI, entry 1).
  • 38
    • 0039938512 scopus 로고    scopus 로고
    • note
    • Enolate F is not axially chiral along the C(1)-N axis even if the bond rotation is restricted at -78 °C. The 2,3-dihydroxazole ring in G is supposed to be nearly planar.
  • 39
    • 0043162336 scopus 로고
    • The most stable conformation H of 25c was generated by MCMM search with MM3* force field using MacroModel V6.0: a) G. Chang, W. C. Guida and W. C. Still: J. Am. Chem. Soc. 111 4379-4386 (1989).
    • (1989) J. Am. Chem. Soc. , vol.111 , pp. 4379-4386
    • Chang, G.1    Guida, W.C.2    Still, W.C.3
  • 40
    • 0040531402 scopus 로고    scopus 로고
    • note
    • The steric interaction between KHMDS and Boc or MOM group at the transition state for the deprotonation is supposed to influence the enantioselectivity in the formation of chiral enolate E more significantly than the conformational preference of 25c.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.