34335-17-6Relevant articles and documents
Intramolecular cyclization of (2-functionalized allyl)trimethylsilane with acid chloride. Synthesis of two guaianolide-type α-methylene γ-lactones
Kuroda,Kobayashi,Koito,Anzai
, p. 1947 - 1961 (2001)
α-Methylene γ-lactone fused to seven-membered carbocycle was synthesized by intramolecular cyclization of (2-ethoxycarbonylallyl)trimethylsilane or (2-acetoxymethylallyl)trimethylsilane with acid chloride. The former was found to be a better way for seven-membered carbocyclization, while the latter method was applicable to the synthesis of α-methylene γ-lactones fused to eight- and fourteen-membered carbocycles. Both guaian-8,12- and 6,12-olide type of compounds were synthesized by this method, in which the cyclization reaction proceeded stereoselectively. It was also found that both (Z)- and (E)-allylsilanes afford the same stereoisomer as the major product.
Room temperature ambient pressure (RTAP)-hydroformylation in water using a self-assembling ligand
Straub, Alexander T.,Otto, Marina,Usui, Ippei,Breit, Bernhard
supporting information, p. 2071 - 2075 (2013/08/23)
We herein demonstrate a hydroformylation at room temperature and ambient pressure (RTAP) using our Rh/6-DPPon (1) system in aqueous media. The hydrogen bonding network of the ligand backbone stays intact, exemplified by the excellent regioselectivity for the linear aldehyde. Various substrates with different functional groups (with some prone to hydrolysis) are stable under the applied conditions and can undergo hydroformylation resulting in good yields. Copyright
Instrumental analysis of terminal-conjugated dienes for reexamination of the sex pheromone secreted by a nettle moth, parasa lepida lepida
Islam, Azharul,Yamakawa, Rei,Do, Nguyen Duc,Numakura, Naoko,Suzuki, Toshiro,Ando, Tetsu
experimental part, p. 1156 - 1162 (2010/03/03)
Conjugated dienyl compounds make one of the main groups of lepidopteran sex pheromones, and GC has been frequently used to determine the configurations of the double bonds. However, the separation of two geometric isomers of a terminal-conjugated diene, such as 7,9-decadien-1-ol secreted by a nettle moth Parasa lepida lepida (Limacodidae), is assumed to be difficult. In order to clarify the chromatographic separation of the terminal dienes, 7,9-decadienyl and 9,11-dodecadienyl compounds (alcohols, acetates, and aldehydes) were analyzed by GC and HPLC. On a capillary GC column, the (E)-isomers flowed out slightly faster than the corresponding (Z)-isomers, but their peaks almost overlapped. On the other hand, HPLC equipped with an ODS column completely separated the two geometric isomers examined and the (Z)-isomers eluted from the column faster than the (E)-isomers without dependence on a functional group. In addition to undergoing direct HPLC analysis without derivatization, the dienyl alcohols were converted into 3,5-dinitrobenzoates and analyzed by LC-ESI-MS operated under the same reversed-phase condition. The two separated geometric isomers were sensitively monitored by negative ions at m=z 211, M, M+1, M+17, and M+31, which were characteristically derived from the benzoates. Based on these results, a pheromone extract of P. l. lepida was examined, and it was confirmed that the female moths exclusively produced the (Z)-isomer of the 7,9-diene. Furthermore, a GC-EAD analysis and a field evaluation with both geometrical isomers indicated that the mating communication of P. l. lepida is predominantly mediated with the (Z)-isomer.
Synthesis of medium- and large-sized lactones in an aqueous-organic biphasic system
Kinoshita, Hidenori,Shinokubo, Hiroshi,Oshima, Koichiro
, p. 2397 - 2400 (2007/10/03)
(Chemical Equation Presented) Saving solvent: An aqueous-ethyl acetate biphasic system allows an efficient synthesis of medium- and large-sized lactones by an intramolecular Tsuji-Trost reaction (see scheme, n = 1-5). The macrocyclization protocol does not require a large quantity of solvents or a slow-addition technique.
Synthesis and characterization of hexadecadienyl compounds with a conjugated diene system, sex pheromone of the persimmon fruit moth and related compounds
Nishida, Takanobu,Vang, Le Van,Yamazawa, Hiroyuki,Yoshida, Ryuji,Naka, Hideshi,Tsuchida, Koji,Ando, Tetsu
, p. 822 - 829 (2007/10/03)
Hexadecadien-1-ol and the derivatives (acetate and aldehyde) with a conjugated diene system have recently been identified from a pheromone gland extract of the persimmon fruit moth (Stathmopoda masinissa), a pest insect of persimmon fruits distributed in
Stereoselective synthesis of cyclic ethers by intramolecular trapping of dicobalt hexacarbonyl-stabilized propargylic cations
Betancort, Juan M.,Martin, Tomas,Palazon, Jose M.,Martin, Victor S.
, p. 3216 - 3224 (2007/10/03)
The intramolecular attack of a hydroxy group on an exo-biscobalthexacarbonyl propargylic cation provides cyclic ethers with six- to nine-membered rings. The scope and limitations of the methodology are described. The reaction is stereoselective when addit
An efficient synthesis of trans-γ-oxo-α,β-unsaturated carboxylic acids, the intermediates for patulolide A and pyrenophorin
Davis,Bhalerao,Vittal Rao
, p. 656 - 661 (2007/10/03)
An efficient synthesis of intermediates for macrolide antifungals patulolide A 14 and pyrenophorin 16 are described with the key steps involving (i) coupling of the alkyl lithium with α,β-unsaturated aldehyde 8, (ii) the oxidation of the cis-trans mixture
Chemoenzymatic synthesis of ferrulactone II and (2E)-9-hydroxydecenoic acid
Pawar,Sankaranarayanan,Chattopadhyay
, p. 2219 - 2226 (2007/10/03)
A novel and divergent synthesis of the title compounds has been developed. The salient features of the synthesis were use of easily accessible starting material, regioselective organometallic reaction and enzymatic derivation of the key synthons.
Stereoselective intramolecular cyclization of β-alkoxycarbonyl-ω-formylallylsilanes into bicyclic α-methylene-γ-lactones
Nishitani,Nakamura,Orii,Arai,Yamakawa
, p. 822 - 831 (2007/10/02)
α-Methylene-γ-lactones fused to five- and six-membered carbocycles were efficiently synthesized from β-ethoxycarbonyl-ω-formylallylsilane derivatives by means of the intramolecular Hosomi reaction. The formylated allylsilanes (11a, b, 12a and b) were synthesized from ethyl β-trimethylsilylpropionate and ω-tetrahydropyranyloxypentanal (4a) and -hexanal (4b) in several steps. The cyclization reaction of these aldehydes was performed under mild conditions with a high degree of stereocontrol. Treatment of the (E)- and (Z)-isomers of the allylsilanes (11a and 12a) with titanium tetrachloride or boron trifluoride etherate gave a five-membered cis-hydroxy ester (13a). Treatment of the (Z)-allylsilane derivative (11b) with titanium tetrachloride afforded a six-membered cis-hydroxy ester (13b) as a major product together with the trans-isomer (14b), and treatment with boron trifluoride etherate selectively gave the cis-isomer (13b). On the other hand, treatment of (E)-allylsilane (12b) with titanium tetrachloride selectively gave the cis-hydroxy ester (13b), while the use of boron trifluoride etherate exclusively afforded the trans-isomer (14b). These stereoselectivities can be explained in terms of chelated transition models. Lactonization of these hydroxy esters afforded the corresponding fused α-methylene-γ-lactones (16a, 17a and b) in good yields.
