Palladium(II)-catalyzed carbonylation of 3-buten-1-ols and 3-butyn-1-ols: an efficient synthesis of .gamma.-butyrolactones
作者:Yoshinao Tamaru、Makoto Hojo、Zenichi Yoshida
DOI:10.1021/jo00003a036
日期:1991.2
Palladium(II)-catalyzed dicarbonylation of 3-buten-1-ols (1) in the presence of propylene oxide and ethyl orthoacetate in methanol-dichloromethane under carbon monoxide at atmospheric pressure afforded alpha-[(methoxycarbonyl)methyl]-gamma-butyrolactones (2) in good yields. This dicarbonylation reaction occurs via stereospecific cis addition. Under similar conditions, 4-(trimethylsilyl)-3-butyn-1-ols (4a and 4b) undergo dicarbonylation to provide cis-dicarbonylated alpha-methylene-gamma-butyrolactones (5a and 5b, respectively). 4-Alkyl-and 4-aryl-3-butyn-1-ols (4c-g), on the other hand, undergo trans alkoxycarbonylation across the triple bond and selectively furnish E tetrasubstituted alpha-methylene-gamma-butyrolactones (6).
Studies of ring-closing mode of 4-hydroxy-2-vinylidenebutanoates: 5-exo-trig versus 5-endo-dig
作者:Shinji Kitagaki、Daisuke Shibata、Chisato Mukai
DOI:10.1016/j.tetlet.2007.01.037
日期:2007.3
The ring-closing mode of benzyl 4-hydroxy-2-vinylidenebutanoates (5-exo-trig vs 5-endo-dig) could precisely be controlled in a highly selective manner by the proper choice of conditions (solvent and base). (c) 2007 Elsevier Ltd. All rights reserved.
TAMARU, YOSHINAO;HOJO, MAKOTO;YOSHIDA, ZEN-ICHI, J. ORG. CHEM., 56,(1991) N, C. 1099-1105