Synthesis of some carboxylic acid analogs cleaved between the C-2 and C-3 bond of tetramethylcyclopropanecarboxylic acid,and insecticidal activities of their esters.

Furuhata, Akimichi; Hirano, Masachika; Fujimoto, Izumi; Matsui, Masanao

doi:10.1271/bbb1961.51.1633

Cited by 3 publications

(2 citation statements)

References 2 publications

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“…Fine-tuning of the reaction conditions provided a considerably improved access to compound 9 as compared to the original synthesis described much earlier (Scheme 3). [22][23][24] Thus, deprotonation of commercial ethyl senecioate (15) using lithium diisopropylamide (LDA) followed by kinetic quenching with prenyl bromide leads to ethyl lavandulate. Without further characterization this intermediate was subjected to alkaline hydrolysis to give lavandulic acid (16).…”

Section: Resultsmentioning

confidence: 99%

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Transition metals in organic synthesis, Part 98. Transition metal mediated total synthesis of the potent neuronal cell protecting alkaloid (±)-lavanduquinocin

Fröhner¹,

Reddy²,

Knölker³

2012

Arkivoc

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Section: Resultsmentioning

confidence: 99%

“…Without further characterization this intermediate was subjected to alkaline hydrolysis to give lavandulic acid (16). 22 Using optimized reaction conditions, proton-initiated cyclization of 16 afforded crystalline β-cyclolavandulic acid (17) in 78% yield. Reduction of 17 with lithium aluminum hydride provided β-cyclolavandulyl alcohol (18).…”

Section: Resultsmentioning

confidence: 99%

Transition metals in organic synthesis, Part 98. Transition metal mediated total synthesis of the potent neuronal cell protecting alkaloid (±)-lavanduquinocin

Fröhner¹,

Reddy²,

Knölker³

2012

Arkivoc

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Pivaloylmetals (tBu‐COM: M=Li, MgX, K) as Equilibrium Components

Knorr

Böhrer

Schubert

et al. 2012

Chemistry A European J

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Short-lived pivaloylmetals, (H(3)C)(3)C-COM, were established as the reactive intermediates arising through thermal heterolytic expulsion of O=CtBu(2) from the overcrowded metal alkoxides tBuC(=O)-C(-OM)tBu(2) (M = MgX, Li, K). In all three cases, this fission step is counteracted by a faster return process, as shown through the trapping of tBu-COM by O=C(tBu)-C(CD(3))(3) with formation of the deuterated starting alkoxides. If generated in the absence of trapping agents, all three tBu-COM species "dimerize" to give the enediolates MO-C(tBu)=C(tBu)-OM along with O=CtBu(2) (2 equiv). A common-component rate depression by surplus O=CtBu(2) proves the existence of some free tBu-COM (separated from O=CtBu(2)); but companion intermediates with the traits of an undissociated complex such as tBu-COM & O=CtBu(2) had to be postulated. The slow fission step generating tBu-COMgX in THF levels the overall rates of dimerization, ketone addition, and deuterium incorporation. Formed by much faster fission steps, both tBu-COLi and tBu-COK add very rapidly to ketones and dimerize somewhat slower (but still fairly fast, as shown through trapping of the emerging O=CtBu(2) by H(3)CLi or PhCH(2)K, respectively). At first sight surprisingly, the rapid fission, return, and dimerization steps combine to very slow overall decay rates of the precursor Li and K alkoxides in the absence of trapping agents: A detailed study revealed that the fast fission step, generating tBu-COLi in THF, is followed by a kinetic partitioning that is heavily biased toward return and against the product-forming dimerization. Both tBu-COLi and tBu-COK form tBu-CH=O with HN(SiMe(3))(3), but only tBu-COK is basic enough for being protonated by the precursor acyloin tBuC(=O)-C(-OH)tBu(2) .

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Transition metal complexes in organic synthesis, part 42. First total synthesis of the potent neuronal cell protecting substance (±)-lavanduquinocin via iron- and nickel-mediated coupling reactions

Knölker

Fröhner

1998

Tetrahedron Letters

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Synthesis of some carboxylic acid analogs cleaved between the C-2 and C-3 bond of tetramethylcyclopropanecarboxylic acid,and insecticidal activities of their esters.

Cited by 3 publications

References 2 publications

Transition metals in organic synthesis, Part 98. Transition metal mediated total synthesis of the potent neuronal cell protecting alkaloid (±)-lavanduquinocin

Transition metals in organic synthesis, Part 98. Transition metal mediated total synthesis of the potent neuronal cell protecting alkaloid (±)-lavanduquinocin

Pivaloylmetals (tBu‐COM: M=Li, MgX, K) as Equilibrium Components

Transition metal complexes in organic synthesis, part 42. First total synthesis of the potent neuronal cell protecting substance (±)-lavanduquinocin via iron- and nickel-mediated coupling reactions

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