AbstractReadily available cyclobutanols having a butyne‐1,4‐diol moiety underwent a sequential regioselective Meyer–Schuster rearrangement and 1,2‐shift, furnishing α‐hydroxy‐α‐vinylcyclopentanones. The reaction mechanism is consistent with the formation of an allenol intermediate that racemizes under the reaction conditions. Subsequent activation of the allenol leads to an enantio‐ and diastereoselective route to this scaffold.magnified image
AbstractReadily available cyclobutanols having a butyne‐1,4‐diol moiety underwent a sequential regioselective Meyer–Schuster rearrangement and 1,2‐shift, furnishing α‐hydroxy‐α‐vinylcyclopentanones. The reaction mechanism is consistent with the formation of an allenol intermediate that racemizes under the reaction conditions. Subsequent activation of the allenol leads to an enantio‐ and diastereoselective route to this scaffold.magnified image
Synthesis of 2-(2-Oxo-2-phenylethyl)cyclopentanone by Rhodium-Catalyzed Tandem Alkynyl Cyclobutanols Hydroacylation and Semipinacol Rearrangement
作者:Rui Guo、Xueling Mo、Guozhu Zhang
DOI:10.1021/acs.orglett.8b03973
日期:2019.3.1
A rhodium-catalyzed tandem reaction of alkynyl cyclobutanols with salicylaldehydes has been developed. The reaction offers a new and atom-economical approach for the selective preparation of multisubstituted 2-(2-oxo-2-phenylethyl)cyclopentanone in high yields under mild reaction conditions with tolerance of a broad range of substituted alkynyl cyclobutanols and salicylaldehyes. The isolation of intermediate
gold-catalyzed tandem hydration/α-ketol rearrangement of 1-alkynylcyclobutanol derivatives, leading to cyclopentanones bearing an α-hydroxy substituted quaternary center. In the presence of water, coordination of gold catalyst onto alkynyl moiety triggers hydration rather than a direct ringexpansion, which followed by unprecedented Au-catalyzed α-ketol rearrangement. The details and the scope of this method