Beilstein J. Org. Chem.2023,19, 176–185, doi:10.3762/bjoc.19.17
; hydrozirconation; palladium catalysis; Schwartz'sreagent; terpenes; Introduction
Conjugated dienones are recurring structural motifs in natural products. Several biologically relevant compounds carry (2Ε,4E)-unsaturated ketones or the corresponding esters or amides. Selected examples are clifednamide H (1) which
enone building blocks 23 for the synthesis of clifednamides [54][62]. The addition of Schwartz'sreagent proceeds as a syn-addition affording (E)-alkenylzirconocenes 24 from terminal alkynes [28]. Based on these precedents from the literature, we surmised that it might be possible to establish a related
with Schwartz'sreagent and our work [54][55][57][58][61][62].
Synthesis of substituted enynes 25f–o via Corey–Fuchs reaction and Hunsdiecker reaction.
Synthesis of non-natural (a) and natural (b) dienone-containing terpenes: synthesis of β-ionone (3).
Synthesis of enynes 25 via Corey–Fuchs reaction
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Graphical Abstract
Scheme 1:
Examples of biologically active compounds with (2Ε,4E)-unsaturated ketone units.