(Z)-. alpha.-(trimethylsilyl). alpha.,. beta.-unsaturated esters. Their stereoselective conversion into. alpha.,. beta.-and. beta.,. gamma.-unsaturated esters and. beta.,. …

MR Najafi, ML Wang, G Zweifel

文献索引：Najafi, M. Ramin; Wang, Mei-Ling; Zweifel, George Journal of Organic Chemistry, 1991 , vol. 56, # 7 p. 2468 - 2476

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被引用次数: 12

摘要

Deprotonation of methyl (2)-a-(trimethylsilyl) a,,% unsaturated esters with lithium diisopropylamide (LDA) or with lithium hexamethyldisilazide (LHMDS) in the presence of hexamethylphosphoramide (HMPA) ae an activator, followed by protonation of the intermediate dienolates with methanol, produces stereoselectively the desilylated (E)-3- alkenoic esters. Trapping the dienolates with chlorotrimethylsilane instead of methanol ...