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Volumn , Issue 13, 2009, Pages 2133-2136

A stereodivergent enantioselective approach to the C5-C8 segment of berkelic acid

Author keywords

Allyl vinyl ether; Asymmetric catalysis; Berkelic acid; Claisen rearrangement; Dithiane

Indexed keywords

BERKELIC ACID; QUINONE DERIVATIVE; UNCLASSIFIED DRUG;

EID: 68949167290     PISSN: 09365214     EISSN: 14372096     Source Type: Journal    
DOI: 10.1055/s-0029-1217546     Document Type: Article
Times cited : (8)

References (28)
  • 15
    • 68949174361 scopus 로고    scopus 로고
    • R(E,Z) = 38.0 min; baseline separation with 200 mg/injection.
    • R(E,Z) = 38.0 min; baseline separation with 200 mg/injection.
  • 20
    • 29444451549 scopus 로고    scopus 로고
    • For applications of the CAGC in total synthesis, see: d
    • For applications of the CAGC in total synthesis, see: (d) Pollex, A.; Hiersemann, M. Org. Lett. 2005, 7, 5705.
    • (2005) Org. Lett , vol.7 , pp. 5705
    • Pollex, A.1    Hiersemann, M.2
  • 23
    • 68949182243 scopus 로고    scopus 로고
    • The relative and absolute configuration was assigned based on the established stereochemical course of the CAGC. The enantiomeric excess was determined by Mosher ester 1H NMR analysis. To synthesize Mosher esters, aldehydes 14 or 18 were reduced to the corresponding primary alcohols with NaBH4 in methanol, followed by esterification with Mosher's acid.17
    • 17
  • 28
    • 68949176014 scopus 로고    scopus 로고
    • α-Keto Ester 6: To a solution of [Cu{(S,S)-tert- Bu-Box}(H2O)2](SbF6)2 (12; 81 mg, 0.094 mmol, 8 mol, in CH2Cl2 (3 mL, 3 mL/mmol 6) was added (Z,Z)-7 (0.5 g, 1.18 mmol, 1 equiv) in CH2Cl2 (3 mL, 3 mL/mmol 6) at r.t. The solution was stirred for 24 h, then the solvent was evaporated and the residue filtered through a short plug of silica gel (cyclohexane-EtOAc, 1:1, Evaporation of the solvent and purification by flash chromatography (cyclohexane-EtOAc, 50:1→20:1) furnished 6 (478 mg, 96, as a clear oil. R f, 0.34 (cyclohexane-EtOAc, 10:1, 1H NMR (CDCl 3, 400 MHz, δ, 7.62-7.64 (m, 4 H, 7.36-7.45 (m, 6 H, 5.81 (ddd, J, 8.7, 10.3, 17.3 Hz, 1 H, 5.00-5.08 (m, 2 H, 3.80 (s, 3 H, 3.65-3.67 (m, 2 H, 3.56-3.63 (m, 1 H, 2.67-2.73 (m, 1 H, 1.11 d, J, 6.8 Hz, 3
    • 2.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.