Efficient synthesis of the cyclopentanone fragrances (Z)-3-(2-oxopropyl)-2-(pent-2-en-1-yl)cyclopentanone and Magnolione®
作者:Guojun Pan、Robert M. Williams
DOI:10.1016/j.tet.2013.11.066
日期:2014.1
This paper describes the selective syntheses of two cis-isomer-enriched cyclopentanone fragrances: (Z)-3-(2-oxopropy1)-2-(pent-2-en-1-yl)cyclopentanone (four steps, 62% overall yield, 67% cis) and Magnolione (R) (five steps, 60% overall yield, 56% cis). In addition, the asymmetric synthesis of (3aR,7aS)-5-methyl-2,3,3a,4,7,7a-hexahydro-1H-inden-1-one as well as (3a'R,7a/S)-5'-methy1-2',3',3a',4',7',7a'-hexahydrospiro[[1,3]dioxolane-2,1'-indene] has been realized by an efficient kinetic resolution, which enables the selective synthesis of the 25,3R-isomer-enriched 3 and 4. (C) 2013 Elsevier Ltd. All rights reserved.
Unified Total Syntheses of Fawcettimine Class Alkaloids: Fawcettimine, Fawcettidine, Lycoflexine, and Lycoposerramine B
作者:Guojun Pan、Robert M. Williams
DOI:10.1021/jo3006045
日期:2012.5.18
syntheses of the lycopodiumalkaloids fawcettimine, fawcettidine, lycoflexine, and lycoposerramine B have been accomplished through an efficient, unified, and stereocontrolled strategy that relies on a Diels–Alder reaction to construct the cis-fused 6,5-carbocycles with one all-carbon quaternary center. Access to the enantioselective syntheses of both antipodes of those alkaloids can be achieved by