112456-40-3Relevant academic research and scientific papers
Highly efficient heterogeneous polymer-supported Sharpless alkene epoxidation catalysts
Karjalainen,Hormi,Sherrington
, p. 1563 - 1575 (1998)
More widespread, and cost effective, use of soluble transition metal complex asymmetric catalysts would be achieved if highly efficient heterogeneous analogues could be developed. We now report the synthesis of branched/crosslinked poly(tartrate ester)s and their use as heterogeneous ligands for the complexation of Ti(O(i)Pr)4, and use of the resulting insoluble catalysts in the asymmetric epoxidation of a range of trans- allylic alcohols employing t-butylhydroperoxide (tBHP) as the oxidant. Isolated yields of epoxides of up to 80%, with enantiomeric excesses up to 98% have been achieved. Removal and recovery of the polymer catalyst is by simple filtration at the end of reactions. The influence of the ratio of polymer-ligand-titanium, and the polymer backbone molecular architecture on the activity and enantioselectivity of the catalysts has been assessed. Typically polymer branching ratios of 3-11% and a polymer-ligand:titanium ratio of 2:1 yield the optimum results.
Scalemic 12-hydroxyambliofuran and 12-acetoxy-ambliofuran, five tetracyclic furanoditerpenes and a furanosesterterpene from Spongia sp
Searle, Philip A.,Molinski, Tadeusz F.
, p. 9893 - 9908 (1994)
Eight new compounds were isolated from a Western Australian sponge Spongia sp., including 12-hydroxyambliofuran (5), its acetate ester 6, five new tetracyclic diterpenes 7 -bd11 and the epoxyfuranosesterterpene carboxylic acid 12. Compounds 5 and 6, each isolated as a 3:1 mixture of enantiomers as determined by a modified Mosher's ester method and chiral lanthanide NMR shift studies, are rare examples of scalemic marine natural products.
Enantioselective synthesis of 3-hydroxycitronellic acid isolated from Ceratocystis fimbriata sp. platani
Fkyerat, Abdellatif,Burki, Nicolas,Tabacchi, Raffaele
, p. 2023 - 2028 (1996)
(3S)- and (3R)-3-hydroxy-citronellic acid were obtained by Sharpless epoxidation of geraniol, followed by reduction of the epoxide and subsequent oxidation of the primary alcohol to a carboxylic acid. This enantioselective approach allowed us to assign absolute configuration 3R to the naturally occuring monoterpene derivative.
REGIOSELECTIVE EPOXIDATION OF GERANIOL WITH m-CHLOROPERBENZOIC ACID IN EMULSION SYSTEMS
Nakamura, Masaki,Tsutsui, Nobuyasu,Takeda, Tokuji,Tokoroyama, Takashi
, p. 3231 - 3232 (1984)
Oxidation of geraniol with m-chloroperbenzoic acid (m-CPBA) in emulsion systems gave 2,3-epoxygeraniol selectively in high yield.
A short and efficient synthetic strategy for the total syntheses of (S)-(+)- and (R)-(-)-Plakolide A
Mohapatra, Debendra K.,Pramanik, Chinmoy,Chorghade, Mukund S.,Gurjar, Mukund K.
, p. 5059 - 5063 (2007)
Concise and efficient total syntheses of anticancer agents (S)-(+)-Plakolide A and (R)-(-)-Plakolide A were accomplished in eight steps and an overall yield of 39 % starting from geraniol. The key steps in our strategy are Sharpless asymmetric epoxidation, double elimination, and Stille coupling reactions. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Identification of carbon-centred radicals derived from linalyl hydroperoxide, a strong skin sensitizer: A possible route for protein modifications
Bezard, Michael,Gimenez-Arnau, Elena,Meurer, Bernard,Grossi, Loris,Lepoittevin, Jean-Pierre
, p. 3977 - 3986 (2005)
Few studies are reported on the formation of reactive carbon-centred radical species from toxic xenobiotics. In this paper the formation of carbon radicals derived from the skin sensitizer linalyl hydroperoxide is described using radical trapping and EPR studies. Radical trapping used TMIO as scavenger agent and light, heat or TPP-Fe3+ as radical inducers. EPR spin trapping was based on the use of the parent alcohol, generating the same allyloxyl radical than the hydroperoxide by photolysis of the corresponding nitrite formed with t-BuONO, also playing the role of the spin trap. It is suggested that the generation of these carbon radical species could play an important role for the binding of the hydroperoxide with skin proteins to form antigenic structures, the first step of the skin sensitization mechanism.
Total Syntheses and Determination of Absolute Configurations of Cep-212 and Cep-210, Predicted Biosynthetic Intermediates of Tetrodotoxin Isolated from Toxic Newt
Adachi, Masaatsu,Miyasaka, Tadachika,Kudo, Yuta,Sugimoto, Keita,Yotsu-Yamashita, Mari,Nishikawa, Toshio
, p. 780 - 784 (2019)
Total syntheses of Cep-212 and Cep-210, predicted biosynthetic intermediates of tetrodotoxin isolated from the Japanese toxic newt, have been accomplished from geraniol by an intramolecular hetero Diels-Alder reaction as a key step in a highly stereoselective manner. The success of these syntheses enabled us to determine their absolute configurations by using a chiral normal-phase HPLC/MS analysis of the bis-dinitrobenzene derivative of natural Cep-212 and reference derivatives prepared from chemically synthesized enantiomers.
Selective epoxidation in dense phase carbon dioxide
Pesiri, David R.,Morita, David K.,Glaze, William,Tumas, William
, p. 1015 - 1016 (1998)
Selective epoxidations with transition metal catalysts (V, Ti, Mo) and ButOOH proceed with high conversions and high selectivity in dense phase carbon dioxide.
Asymmetric Synthesis of the Antiviral Diterpene Wickerol A
Liu, Shu-An,Trauner, Dirk
, p. 9491 - 9494 (2017)
Wickerol A (1) is an unusual diterpene with remarkable activity against the H1N1 influenza virus. Its tetracyclic skeleton contains three quaternary carbons and is marked by several syn-pentane interactions which force a six-membered ring into a twist-boat conformation. We present an asymmetric synthesis of wickerol A (1) that is based on a Jung Diels-Alder reaction, an intramolecular alkylation to complete the 6-5-6-6 ring system, and a conjugate addition, all of which overcome considerable steric strain. During the synthesis, we isolated an unexpected cyclopropane that presumably stems from a carbonium ion intermediate.
SYNTHESIS OF (2R,3R)-EPOXYNERAL, A SEX PHEROMONE OF THE ACARID MITE, Caloglyphus sp. (ASTIGMATA: ACARIDAE)
Mori, Naoki,Kuwahara, Yasumasa
, p. 1477 - 1478 (1995)
(2R,3R)-Epoxy-3,7-dimethyl-6-octenal 1a, was identified from an acarid mite Caloglyphus sp. (Astigmata: Acaridae) as the sex pheromone, although its antipode (2S,3S)-epoxyneral 1b is known as a component from a few mite species withou
