jo6b01051_si_001.pdf (4.36 MB)
Modular and Stereodivergent Approach to Unbranched 1,5,9,n-Polyenes: Total Synthesis of Chatenaytrienin‑4
journal contribution
posted on 2016-08-26, 20:03 authored by Juliane Adrian, Christian B. W. StarkAn iterative strategy
for the stereodivergent synthesis of unbranched
1,5,9,n-polyenes (and -polyynes) was investigated. Starting from a
terminal alkyne the iteration cycle consists of a C3 extension
(allylation), a chemoselective hydroboration, an alkyne reduction,
and an oxidation of the associated alcohol with subsequent C1 homologation. Double bond geometry is controlled using stereoselective
alkyne reductions, employing either the Lindlar hydrogenation protocol
or an aluminum hydride reduction. In a model sequence it was demonstrated
that the strategy is applicable to the synthesis of 1,5,9,n-polyenes
with any possible double bond configuration accessible in equally
high efficiency and selectivity. It is worth noting that our approach
does not require any protecting group chemistry. Furthermore, using
the same strategy, the first total synthesis of chatenaytrienin-4,
the proposed unsaturated biosynthetic precursor of the bis-THF acetogenin
membranacin, was examined. Thus, the all-cis 1,5,9-triene
natural product was prepared in 15 steps from commercially available
starting materials in 6% overall yield.
History
Usage metrics
Categories
Keywords
iteration cycleC 1 homologationC 3 extensionstereoselective alkyne reductionsTotal Synthesisbiosynthetic precursor15 stepsbond configurationchemoselective hydroborationn-polyenemodel sequenceiterative strategyterminal alkyneDouble bond geometrystereodivergent synthesisbis-THF acetogenin membranacinStereodivergent Approachalkyne reductionLindlar hydrogenation protocolaluminum hydride reductiongroup chemistry
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC