Studies on halomethylvinyl cyclopropanecarboxylic acids and their esters. Part IV. Synthesis of chloromethylvinylcyclopropanecarboxylic acid derivatives.

Muramatsu, Shigeki; Nakada, Yasuo; Ide, Junya

doi:10.1271/bbb1961.49.751

Cited by 4 publications

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“…The three ketones coelute and are isolated as a yellow oil. They have been identified and characterized by 1 H and 13 C NMR spectroscopic data, which agree with the published data for these compounds. − The C H resonance in the 1 H NMR spectrum of compound 9a is characterized as a distinctive triplet of septets with three- and four-bond coupling to the C H 2 ( 3 J HH = 7.2 Hz) and C Me 2 ( 4 J HH = 1.4) protons, respectively.…”

Section: Resultssupporting

confidence: 82%

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Functionalization of Methane Initiated by Cp*W(NO)(CH₂CMe₃)(η³-CH₂CHCMe₂)

et al. 2016

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Cp*W(NO)(CH 2 CMe 3 )(η 3 -CH 2 CHCMe 2 ) (1) initiates a stepwise conversion of methane into unsymmetrical unsaturated ketones. The first step involves the activation of methane by 1 in cyclohexane to form Cp*W(NO)(CH 3 )(η 3 -CH 2 CHCMe 2 ) (2) in good yield as a mixture of two isomers that differ with respect to the exo/endo orientation of their allyl ligands. Subsequent exposure of a cyclohexane solution of 2 to 500 psig of CO pressure and 75 °C for 3 h results in the 1,1-insertion of CO into the W−CH 3 linkage of 2 and formation of the yellow acyl complex Cp*W(NO)(C(O)CH 3 )(η 3 -CH 2 CHCMe 2 ) (5). Additional carbonylation of 2 can be effected by maintaining the cyclohexane solution at 750 psig of CO pressure and 75 °C for 3 days, a process that results in the formation of the isomeric η 2 -unsaturated-ketone complexes Cp*W(NO)(CO)(η 2 -Me 2 CCHCH 2 C(O)CH 3 ) (6a) and Cp*W(NO)(CO)(η 2 -H 2 CCHCMe 2 C(O)CH 3 ) (6b) in a 60:40 ratio. Finally, exposure of 2 to CO under more forcing conditions (1000 psig at 170 °C for 3 days) produces Cp*W(NO)(CO) 2 (8) and the isomeric β,γ-unsaturated ketones 5-methylhex-4-en-2-one (9a), 3,3-dimethylpent-4-en-2-one (9b), and trans-5methylhex-3-en-2-one (9c) in a 92:5:3 ratio. Similarly, maintaining an Et 2 O solution of 1 at 1000 psig of CO and 170 °C for 3 days results in the complete conversion of 1 into 8 and liberates 2,2,7-trimethyloct-6-en-4-one (10). The final organometallic complex, 8, can be reconverted into the initial reactant 1 via Cp*W(NO)Cl 2 , which in turn is cleanly obtained by treatment of 8 with PCl 5 . All new compounds have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of five of them have been established by single-crystal X-ray crystallographic analyses. ■ RESULTS AND DISCUSSIONModified Synthesis of Complex 1. Compound 1 is best synthesized via a modification of the published procedure, 4

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Section: Resultssupporting

confidence: 82%

“…These data agree well with those previously reported. , IR (cm –1 ): 1712 (w, ν CO ). 1 H NMR (400 MHz, CDCl 3 ): δ 1.64 (s, 3H), 1.76 (s, 3H), 2.15 (s, 3H), 3.12 (d, J = 7.2 Hz, 2H,), 5.31 (tsep, J = 7.2, 1.4 Hz, 1H).…”

Section: Experimental Sectionsupporting

confidence: 93%