Pt-Catalyzed Tandem Epoxide Fragmentation/Pentannulation of Propargylic Esters
作者:Brian G. Pujanauski、B. A. Bhanu Prasad、Richmond Sarpong
DOI:10.1021/ja061549m
日期:2006.5.1
A Pt-catalyzed pentannulation of propargylic esters containing an epoxide moiety has been developed. The present transformation achieves the formation of cyclopentenone products as single diastereomers in good yields. The observed products likely form from pyran intermediates that undergo an oxa-6pi electrocyclic ring opening to a functionalized dienone, followed by ring closure with an accompanying acyl shift.
Palladium(II)- and mercury(II)-catalyzed rearrangements of propargyl acetates
作者:Patrick A. Caruana、Alison J. Frontier
DOI:10.1016/j.tet.2007.08.008
日期:2007.10
The scope and utility of the metal-catalyzed rearrangement of propargyl acetates first reported by Rautenstrauch were expanded. Treatment of a series of appropriate acetate substrates with Pd(II)- and Hg(II)-catalysts afforded synthetically useful fused 5,6-bicyclic-1,4-cyclopentadienyl acetates and 2-cyclopentenones. It was found that the substituents at the terminal alkynyl and alkenyl positions