62695-68-5Relevant academic research and scientific papers
Donor Rhodium Carbenes by Retro-Buchner Reaction
Mato, Mauro,Echavarren, Antonio M.
supporting information, p. 2088 - 2092 (2019/01/25)
Rhodium carbenes are key intermediates in a range of cycloadditions and insertion reactions. Herein, we report the first generation of donor RhII carbenes by decarbenation of 7-substituted 1,3,5-cycloheptatrienes. This discovery unlocks an improved retro-Buchner-cyclopropanation sequence, a Si?H insertion reaction for a broad-scope synthesis of allylsilanes, and a new method for the vinylogation of aldehydes. The last strategy led to the development of an iterative synthesis of E-polyenes, and to the total synthesis of navenones B and C.
1,n-rearrangement of allylic alcohols promoted by hot water: Application to the synthesis of navenone B, a polyene natural product
Li, Pei-Fang,Wang, Heng-Lu,Qu, Jin
, p. 3955 - 3962 (2014/05/20)
It was reported for the first time that hot water as a mildly acidic catalyst efficiently promoted 1,n-rearrangement (n = 3, 5, 7, 9) of allylic alcohols. In some cases, the rearrangement reactions joined isolated C-C double or triple bonds to generate conjugated polyene or enyne structure motifs. We used the 1,3-rearrangement reaction of an allylic alcohol in hot water as part of an attractive new strategy for construction of the polyene natural product navenone B by iterative use of a Grignard reaction, a 1,3-rearrangement of the resulting allylic alcohol, and subsequent oxidation of the rearranged product.
Four- and eight-carbon homologation of benzaldehyde by (1Z,3Z)- butyltelluro-1,3-butadiene: Synthesis of navenone B: Alarm pheromone of the mollusk navanax inermis
Dabdoub, Miguel J.,Dabdoub, Vania B.,Baroni, Adriano C.M.,Barbosa, Sandro L.
experimental part, p. 942 - 950 (2012/02/01)
Four- and eight-carbon homologation of benzaldehydes is described. The hydrotel-luration of (Z)-1-methoxy-but-1-en-3-ynes 1 afforded (1Z,3Z)-1-butyltelluro-4-methoxy-1,3-butadiene 2, this compound 2 underwent a Te=Li exchange reaction, and the butadienyl-lithium 3 obtained reacted with benzaldehyde to form the corresponding allylic alcohol 4 with total retention of configuration. The allylic alcohol 4a formed underwent acidic hydrolysis, resulting in 5-phenyl-(2E,4E)-dienal 5 (four-carbon homologation of benzaldehyde). Product 5 reacted with the butadienyllithium 3, affording the alcohol 9-phenyl-(1-Z,3Z,6E,8E)-1-methoxy-5-hydroxy-nonatetraene 6, which was hydrolyzed or spontaneously transformed into 9-phenyl-(2E,4E,6E,8E)-tetraenal 7, completing the eight-carbon homologation of benzaldehyde. Reaction of 9-phenyl-nona-(2E,4E,6E,8E)-tetraenal 7 with methyllithium in tetrahydrofuran afforded (3E,5E,7E, 9E)-10-phenyl-deca-3,5,7,9-tetraen-2-ol 8. The product of the reaction described was employed in the synthesis of (3E,5E,7E,9E)-10-phenyl- deca-3,5,7,9-tetraen-2-one 9, which is known as navenone B, an alarm pheromone of the mollusk Navanax inermis. Taylor & Francis Group, LLC.
Sn/Li exchange reactions in 1,ω-distannylated conjugated trienes and tetraenes: An enabling step for polyene synthesis
Burghart, Jochen,Brueckner, Reinhard
experimental part, p. 150 - 165 (2011/03/18)
Successive treatments of (1E,3E,5E)- or (1E,3Z,5E)-1,6-bis(tributylstannyl) hexa-1,3,5-triene with nBuLi and butanal rendered polyenyl alcohols resulting from one Sn/Li exchange reaction and exhibiting complete retention of the configuration of all C=C bonds. Mono- or dimethylated all-E-configured 1,6-distannylated conjugated trienes as well as all-E-1,8-bis(tributylstannyl) octa-1,3,5,7-tetraene and dimethylated congeners thereof reacted similarly. The respective Sn/Li exchange reactions affected the substructure Bu 3Sn-CH=CH with a 93-94:7-6 preference over Bu3Sn-CMe=CH and with a 90:10 preference over Bu3Sn-CH=CMe. all-E-1-Lithio-6- (tributylstannyl)hexa-1,3,5-triene was incorporated into navenone B after Negishi coupling and into (-)-cicutoxin after acylation. NMR spectroscopy of our navenone B specimen revealed that certain resonances were misassigned previously. Molecular tinkertoy: all-E-1,6-(Tributylstannyl)hexa-1,3,5-triene, all-E-1,8-(tributylstannyl)octa-1,3,5,7-tetraene, and related bis(tributylstannylated) polyenes undergomono-Sn/Li exchange reactions. They set the stage for terminus-differentiating functionalizations, which provide inter alianavenone B and (-)-cicutoxin.
Simple synthesis of conjugated all-(E)-polyenic aldehydes, ketones, and esters using chemoselective cross-metathesis and an iterative sequence of reactions: Application to the synthesis of navenone B
Bouzbouz, Samir,Roche, Christophe,Cossy, Janine
scheme or table, p. 803 - 807 (2009/06/19)
By using a very simple sequence of reactions such as allylation, acetylation, chemoselective cross-metathesis, and elimination, even and odd conjugated all-(E)-polyenes can be synthesized from very simple alkenes. Georg Thieme Verlag Stuttgart.
Stereoselective approaches to (E,E,E) and (Z,E,E)-α-chloro-ω- substituted hexatrienes: Synthesis of all E polyenes
Crousse, Benoit,Mladenova, Margarita,Ducept, Pascal,Alami, Mouad,Linstrumelle, Gerard
, p. 4353 - 4368 (2007/10/03)
Two stereocontrolled synthetic approaches to (E,E,E) and (Z,E,E)-α- chloro-ω-substituted hexatrienes 1-3 are described starting from unsaturated compounds 4-6. The key step of the first approach is based on the palladium- catalyzed rearrangement of bis-allylic acetates 4 and 5 and the second one is based on the stereoselective reduction of homopropargylic alcohols 6 followed by an elimination reaction. These stable chlorotrienes 1-3 are suitable synthetic intermediates for the construction of navenone B and all E polyenes (trienes, tetraenes, hexaenes and heptaenes).
Stereoselective synthesis of polyenic alarm pheromones of cephalaspidean molluscs
Alvarez, Rosana,Herrero, Maria,Lopez, Susana,De Lera, Angel R.
, p. 6793 - 6810 (2007/10/03)
The stereospecific thallium-accelerated palladium-catalyzed cross- coupling of 1-alkenyl boronic acids and 1-alkenyl iodides (the Suzuki reaction) is the key step in an efficient approach to several polyenic pheromones isolated from cephalaspidean opisthobranch molluscs.
Stereocontrolled synthesis of (E,E,E)-chlorotrienes: Efficient intermediates for the construction of all E conjugated polyenes
Crousse, Benoit,Alami, Mouad,Linstrumelle, Gerard
, p. 5297 - 5300 (2007/10/03)
Stereoselective reduction of conjugated homopropargylic alcohols 1 followed by an elimination reaction, allows an efficient approach to stereodefined (E,E,E)-chlorotrienes. The interest of these chlorotrienes was illustrated by a stereocontrolled synthesis of navenone B and all E conjugated polyenes (trienes, tetraenes and hexaenes).
