Bioinspired Asymmetric Total Synthesis of Emeriones A–C**
作者:Sven Jänner、Daniel Isak、Yuli Li、Kendall N. Houk、Aubry K. Miller
DOI:10.1002/anie.202205878
日期:2022.8.8
The emeriones, three highly oxidized and densely functionalized polyketides, were synthesized from two enantioenriched fragments in a Stille-8π/6π sequence, followed by late-stage stereo- and chemoselective oxidations. This work enabled the structural revision of emerione C.
A New Directing Mode for Singlet Oxygen Ene Reactions: The Vinylogous Gem Effect Enables a <sup>1</sup>O<sub>2</sub> Domino Ene/[4 + 2] Process
作者:Axel G. Griesbeck、Alan de Kiff
DOI:10.1021/ol4009602
日期:2013.5.3
The singletoxygenreactions of 4-methyl-2,4-hexadienoates E,E- and E,Z-4 proceed in a highly mode selective and regioselective domino process. The initial product is the allylic hydroperoxide 5 directed by a vinylogous gem effect. The subsequent 1O2 [4 + 2] cycloaddition delivers a 3:2 diastereoisomeric mixture of 1,2-dioxanes 8 in a one-pot process. The identical protocol delivers from the more reactive