72345-84-7Relevant academic research and scientific papers
Isotope sensitive branching and kinetic isotope effects to analyse multiproduct terpenoid synthases from Zea mays
Gatto, Nathalie,Vattekkatte, Abith,K?llner, Tobias,Degenhardt, J?rg,Gershenzon, Jonathan,Boland, Wilhelm
supporting information, p. 3797 - 3800 (2015/03/30)
Multiproduct terpene synthases TPS4-B73 and TPS5-Delprim from Zea mays exhibit isotopically sensitive branching in the formation of mono- and sesquiterpene volatiles. The impact of the kinetic isotope effects and the stabilization of the reactive intermediates by hyperconjugation along with the shift of products from alkenes to alcohols are discussed.
Terpenes and Terpene Derivatives, XVIII. - Concerning the Preparation of rac-γ-Curcumene
Weyerstahl, Peter,Marschall-Weyerstahl, Helga,Scholz, Stefan
, p. 1021 - 1029 (2007/10/02)
Preparation of pure γ-curcumene (3) described by Birch in 1949 via dehydratization of the alcohol 5 with SOCl2/pyridine was not reproducible.Mixtures of α-, β-, and γ-curcumene (1-3) were obtained even with POCl3/pyridine or Burgess reagent.Analogously the secondary alcohol 20 yielded mixtures of 3 and the 1,3-dienes 21 and (presumably) 22. - Li/NH3 reduction of the tert. benzyl alcohol 8 afforded after work-up directly the dienone 15 which with MeLi gave the dehydro derivative 16 of zingiberenol (17).
Selective Synthesis of Either Complex Aromatic Alkenes or (1,4-Cyclohexadienyl)alkenes by Tandem Arylation-Multistep Reduction of α,β,γ,δ-Unsaturated Ketones
Zilenovski, Judith S. Ryan,Hall, Stan S.
, p. 4139 - 4142 (2007/10/02)
(1,4-Cyclohexadienyl)alkenes are conveniently prepared in excellent isolated yields from α,β,γ,δ-unsaturated ketones by tandem alkylation-multistep reductions.By this one-pot procedure, complex diene benzyl alkoxides, generated in situ by arylation of α,β,γ,δ-unsaturated ketones with organolithium reagents, are reduced by a multistep reduction process in lithium-ammonia-ethanol to the corresponding (1,4-cyclohexadienyl)alkenes.Examples include the synthesis of 2-methyl-6-(1,4-cyclohexadien-1-yl)-2-heptene (7a), (+/-)-β-curcumene (7b), 2-methyl-6-(4-methoxy-1,4-cyclohe xadien-1-yl)-2-heptene (7c), 1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-(1,4-cyclohexadien-1-yl)butane (9a), 1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-(4-methyl-1,4-cyclohexadien-1-yl)butane (9b), and 1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-(4-methoxy-1,4-cyclohexadien-1-yl)butane (9c) using phenyllithium, p-tolyllithium, and p-methoxyphenyllithium with 6-methyl-3,5-heptadien-2-one (1) and β-ionone (2), respectively.In contrast, use of the corresponding Grignard reagents prepared by the Rieke procedure results in the selective synthesis of the corresponding aromatic alkene.Examples include the synthesis of 2-methyl-6-phenyl-2-heptene (8a), (+/-)-α-curcumene (8b), 2-methyl-6-(p-methoxyphenyl)-2-heptene (8c), 1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-phenylbutane (10a), 1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-(4-tolyl)butane (10b), and 1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-(p-methoxyphenyl)butane (10c) using phenylmagnesium bromide, p-tolylmagnesium bromide, and p-methoxyphenylmagnesium bromide with 6-methyl-3,5-heptadien-2-one (1) and β-ionone (2), respectively.The latter series of results suggest that some species, present in the Grignard sequence, is preventing the 1,4-reduction (Birch reduction) of the aromatic ring.
TERPENE UND TERPENDERIVATE-IX α-CURCUMEN, β-CURCUMEN UND ar-TURMERON DURCH ALKYLIERUNG VON C5- UND C10-DITHIANEN
Bokel, H. H.,Hoppmann, A.,Weyerstahl, P.
, p. 651 - 654 (2007/10/02)
The dithiane 11 is alkylated with prenyl bromide to give 12.Hydrogenolysis of 12 with Raney-Nickel yields α-curcumene (6), hydrolysis of 12 gives the ketone 13.Prenal dithiane (14) is alkylated with 8 to give 15. ar-Turmerone (16) is formed by hydrolysis of 15.Reaction of 15 with sodium in liquid ammonia leads to a mixture of α-curcumene (6) and β-curcumene (10).
