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Volumn 45, Issue 22, 2004, Pages 4315-4318

Highly diastereoselective alkylation of vicinal dianions of chiral succinic acid derivatives: A new general strategy to (R)-β-arylmethyl-γ- butyrolactones

Author keywords

butyrolactone; Chiral succinic acid; Vicinal dianion

Indexed keywords

1,4 BIS(3,4 DIMETHYL 2 OXO 5 PHENYLIMIDAZOLIDIN 1 YL)BUTANE 1,4 DIONE; ANION; BUTYROLACTONE; LACTONE DERIVATIVE; SUCCINIC ACID DERIVATIVE; UNCLASSIFIED DRUG;

EID: 2342498603     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2004.04.008     Document Type: Article
Times cited : (12)

References (40)
  • 34
    • 2342564520 scopus 로고    scopus 로고
    • note
    • Treatment of 1a with 1 equiv of LDA, followed by reacting with 1 or 2 equiv of benzyl bromide under the standard conditions provided a low yield of the expected product 3a
  • 35
    • 84987564680 scopus 로고    scopus 로고
    • note
    • 1H NMR and MS. In spite of these results, it was still assumed that the vicinal dianion 2a was generated under the conditions described. This may be due to a strong H-bonded complex between diisopropylamine and the dilithiated derivative. Such interaction effecting incomplete deuteration of the generated lithium derivative was reported by Seebach (Laube, T.; Dunitz, J. D.; Seebach, D. Helv. Chim. Acta, 1985, 68, 1373-1393). The reaction of the vicinal dianion 2a with 2.2 equiv of benzyl bromide at -78°C to room temperature overnight (12-16 h) afforded dibenzylated product 9 in 20-30% yields together with 30-40% yields of the chiral auxiliary, (4S, 5R)-(+)-1, 5-dimethyl-4-phenyl-2-imidazolidinone and compound 11. The formation of 9 supported the presence of the vicinal dianion 2a. Compound 9 was obtained as a single diastereomer and its structure is proposed as shown below. The results also indicated that the vicinal dianion 2a slowly decomposed during warming from -78°C to rt to provide 10 and 11.
  • 37
    • 2342463712 scopus 로고    scopus 로고
    • note
    • 2 using SHELXL-97 to give a final R -factor of 0.0493 and wR=0.1130 (all data). Atomic coordinates, bond lengths, bond angles, and thermal parameters have been deposited with the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, ENGLAND (CCDC 216625)
  • 39
    • 2342516877 scopus 로고    scopus 로고
    • note
    • The chiral auxillary was recovered in 85-95% yields and could be reused without loss of diastereoselectivity
  • 40
    • 2342637843 scopus 로고    scopus 로고
    • note
    • 3)


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.