Synthesis of δ-lactones from 2-alkynyl epoxides and 4-alkynyl-1,3-dioxolan-2-ones by palladium catalysed carbonylation and conjugate nucleophilic addition
Synthesis of δ-lactones from 2-alkynyl epoxides and 4-alkynyl-1,3-dioxolan-2-ones by palladium catalysed carbonylation and conjugate nucleophilic addition
Carbonylation of Alkynyl Epoxides: Synthesis of 5-Hydroxy-2,3-dienoate Esters and 2,3-Dihydrofuran-3-ol Derivatives
作者:Marcelo E. Piotti、Howard Alper
DOI:10.1021/jo971303n
日期:1997.11.1
The carbonylation of alkynyl oxiranes catalyzed by (MePh2)(4)Pd in the presence of 20 atm of carbon monoxide in methanol gives methyl 5-hydroxy-2,3-pentadienoates in good yields. When the reaction is performed on alkynyl oxiranemethanol derivatives, 4,5-dihydrofuran-3-ol derivatives are obtained stereoselectively. These products arise from the spontaneous cyclization of a dihydroxyallenyl ester intermediate.
Synthesis of δ-lactones from 2-alkynyl epoxides and 4-alkynyl-1,3-dioxolan-2-ones by palladium catalysed carbonylation and conjugate nucleophilic addition
作者:Julian G. Knight、Simon W. Ainge、Carl A. Baxter、Timothy P. Eastman、Simon J. Harwood
DOI:10.1039/b006927m
日期:——
Palladium catalysed carbonylation of both 4-alkynyl-1,3-dioxolan-2-ones and alkynyl epoxides occurs under mild conditions to give methyl 5-hydroxy-2,3-dienoates which are converted to γ,δ-unsaturated δ-lactones by tandem conjugate additionâcyclisation with lithium dimethylcuprate or to methyl (E)-5-hydroxypent-3-enoates by stereoselective reduction with sodium borohydride.