Synthesis of labile all-trans-7,8,7′,8′-bis-acetylenic carotenoids by bi-directional Horner–Wadsworth–Emmons condensation
作者:Belén Vaz、Noelia Fontán、Marta Castiñeira、Rosana Álvarez、Ángel R. de Lera
DOI:10.1039/c4ob02144d
日期:——
Two symmetrical C7,C8-acetylenic carotenoids have been stereoselectively prepared using a bi-directional Horner–Wadsworth–Emmons condensation of the C10-dialdehyde and C15-phosphonates.
Synthesis and1H-,13C-, and57Fe-NMR spectra of mono- and bis[tricarbonyl(?4-diene)iron], and (?3-allyl)tetracarbonyliron trifluoroborate complexes
作者:Christoph M. Adams、Giovanni Cerioni、Andreas Hafner、Hermann Kalchhauser、Wolfgang von Philipsborn、Roland Prewo、Andreas Schwenk
DOI:10.1002/hlca.19880710526
日期:1988.8.10
with a (Z)-configuration terminal Me group show steric inhibition of metal complexation resulting in lower yields and formation of tetracarbonyl(η2-diene) and tricarbonyl(η4-heterodiene) complexes as additional products. Regioselective attack by C-nucleophiles at the carbonyl C-atoms of the functional group with or without concomitant 1,3 mogration of the Fe(CO)3 group was used to synthesize polyenes and
<i>endo</i>/<i>exo</i>Stereoselectivity in<i>Diels</i><i>Alder</i>Reactions of<i>α</i>,<i>β</i>-Dialkylated Conjugated Enals to Cyclic 1,3-Dienes: Intermediates in the Synthesis of (−)-<i>β</i>-Santalol and Its Analogs
作者:Christian Chapuis、David Skuy、Jean-Yves de Saint Laumer、Robert Brauchli
DOI:10.1002/cbdv.201400060
日期:2014.10
to α,β-dialkyl conjugated enals 5 are compared with the analogous endo-favored Diels-Alder reaction of cyclohexa-1,3-diene 7. The exo-stereoselectivity is lower in the homologous case of methylcyclopenta-1,3-diene 9. This diastereoselectivity is discussed either in terms of a retro-homo-Diels-Alder reaction, associated with thermodynamic control, or with respect to either a competing hetero-Diels-Alder/Claisen
[EN] PROCESS FOR THE PREPARATION OF BETA-SANTALOL<br/>[FR] PROCÉDÉ DE PRÉPARATION DU BÊTA-SANTALOL
申请人:FIRMENICH & CIE
公开号:WO2013001027A1
公开(公告)日:2013-01-03
The present invention concerns a process for the preparation of a compound of formula (I) in the form of any one of its stereoisomers or mixtures thereof, wherein R represents a C2-C10 group of formula CORa wherein Ra is an alkyl or alkenyl group optionally comprising one or two ether functional groups or is a phenyl or benzyl group optionally substituted by one to three alkyl, alkoxyl, carboxyl, acyl, amino or nitro groups or halogen atoms.
An Economical and Practical Synthesis of<i>rac</i>-(<i>Z</i>)-β-Santalol: Application of a Scriabine-Inspired Reaction to Alkenes Results in the One-Step Preparation of a Key Intermediate
作者:Anthony A. Birkbeck、Xavier Marquet、Pascal Millet、Hervé Pamingle
DOI:10.1002/ejoc.201403219
日期:2014.12
An economical and practicalsynthesis of rac-(Z)-β-santalol was accomplished. The key coupling step is based on a Scriabine-inspiredreaction of a dienyl diacetate substrate and an alkene. The total synthesis was achieved in five steps (longest linear sequence) in 19 % overall yield from cyclopentadiene.