29837-19-2Relevant academic research and scientific papers
Pericyclic Reactions in Nature: Evidence for a Spontaneous -Hydrogen Shift and an 8?e Electrocyclic Ring Closure in the Biosynthesis of Olefinic Hydrocarbons from Marine Brown Algae (Phaeophyceae).
Pohnert, Georg,Boland, Wilhelm
, p. 10235 - 10244 (1994)
The stereochemistry of the algal C11H16 hydrocarbon giffordene 3 results from a spontaneous -sigmatropic hydrogen shift of the thermolabile (1,3Z,5Z,8Z)-undecatetraene 8.An 8?e electrocyclisation of (1,3Z,5Z,7E)-nonatetraene 9 is substantiated for the synthesis of 7-methylcyclooctatriene 5, a product of the Mediterranean brown alga Cutleria multifida.Low temperature syntheses (-30 deg C) of the thermolabile precursors 8 and 9 are described.The activation energies of the -sigmatropic hydrogen shift 8 -> 3 (Ea = 67.4 kJ mol-1) and of the 8?e electrocyclisation 9 -> 5 (Ea = 59.4 kJ mol-1) are the lowest values currently known for natural pericyclic reactions.
Mint composition
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, (2010/07/09)
The present invention relates to a mint composition, which comprises a mint substance and a 1,3,5,8-undecatetraene; and a fragrance-added or flavored product containing the mint composition. The mint composition has enhanced diffusing property and intensity of fragrance or flavor showing a high impact, shows excellent natural feeling and taste and also has excellent durability in fragrance or flavor.
Stereospecific Syntheses and Spectroscopic Properties of Isomeric 2,4,6,8-Undecatetraenes. New Hydrocarbons from the Marine Brown Alga Giffordia mitchellae
Boland, Wilhelm,Schroer, Nora,Sieler, Christiane,Feigel, Martin
, p. 1025 - 1040 (2007/10/02)
Giffordene (=(2Z,4Z,6E,8Z)-2,4,6,8-undecatetraene; 9f) and five stereoisomers are new C11H16 hydrocarbons from the marine brown alga Giffordia mitchellae.Their synthesis is based on non-stereoselective Wittig reactions of (E)-2-alkenals with appropriate acetylenic phosphoranes and subsequent chromatographic separation of the resulting (E/Z)-pairs.The uniform enynes (>98percent purity) are then stereospecifically reduced to (Z)-alkenes with Zn(Cu/Ag) in aq.MeOH at r.t. 13C- and 1H-NMR data of the new tetraenes are presented.Biosynthetically, giffordene (9f) originates from dodeca-3,6,9-trienoic acid via an unstable (3Z,5Z,8Z)-1,3,5,8-undecatetraene followed by a thermally allowed antarafacial 1,7-sigmatropic hydrogen shift to the (2Z,4Z,6E,8Z)-isomer 9f.
Synthesis of Isomeric 1,3,5,8-Undecatetraenes
Marner, Franz-Josef,Boland, Wilhelm,Jaenicke, Lothar
, p. 579 - 584 (2007/10/02)
(3E,5Z,8Z)-1,3,5,8-Undecatetraene (1a) is the smelling principle of the gametes of the brown alga Spermatochnus paradoxus.The synthesis of the isomeric 1,3,5,8-undecatetraenes 1a - c and their spectral properties are described.
