Syntheses and Odor Descriptions of Cyclopropanated Compounds, Part 6

Sakauchi, Hiroyuki; Asao, Hiroki; Hasaba, Tsutomu; Kuwahara, Shigefumi; Kiyota, Hiromasa

doi:10.1002/cbdv.200690058

Cited by 6 publications

(2 citation statements)

References 20 publications

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“…34,35 Spectroscopic and spectrometric data for compounds 4 and 5 are in agreement with those described in the literature. 57,58 On the other hand, reaction between geraniol and the lithium dichlorocarbenoid generated from CH 2 Cl 2 and n-BuLi led to the formation of chlorocyclopropanols 6 (40%), 7 (17%) and the double monochlorocyclopropanation product 8, in low yield (7%) (Table 1, entry 3). Compounds 6 and 7 displayed similar signal patterns in their 13 C NMR spectra, presenting 2 quaternary carbons, 3 methine, 3 methylene and 3 methyl groups.…”

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confidence: 99%

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Chemoselective and stereoselective lithium carbenoid mediated cyclopropanation of acyclic allylic alcohols

et al. 2016

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The reaction of geraniol with different lithium carbenoids generated from n-BuLi and the corresponding dihaloalkane has been evaluated. The reaction occurs in a chemo and stereoselective manner, which is consistent with a directing effect from the oxygen of the allylic moiety. Furthermore, a set of polyenes containing allylic hydroxyl or ether groups were chemoselectively and stereoselectively converted into the corresponding gem-dimethylcyclopropanes in one single step in moderate to good yields mediated by a lithium carbenoid generated in situ by the reaction of n-BuLi and 2,2-dibromopropane.

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Section: Resultsmentioning

confidence: 99%

“…Spectroscopic data of compound 5 were identical to those described in the literature. 58 ((1R*,2S*,3S*)-3-Chloro-2-methyl-2-(4-methylpent-3-en-1-yl) cyclopropyl)methanol (6). (40% yield).…”

Section: General Procedures For Lithium Carbenoid Mediated Cyclopropa...mentioning

confidence: 99%

Chemoselective and stereoselective lithium carbenoid mediated cyclopropanation of acyclic allylic alcohols

et al. 2016

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Present and Future of Cyclopropanations in Fragrance Chemistry

Schröder¹

2014

Chemistry & Biodiversity

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The elaboration of new cyclopropanation methods is expected to make selectively new Δ-compounds available, either as precursors or as new ingredients with superior olfactory impacts. The improvement of cyclopropanation processes through understanding of reaction mechanisms reduces costs and environmental impact. Givaudan is the leading 'Flavor & Frangrance' company which successfully brings Δ-molecules to the market. Javanol(®) , for example, with its unique performance exemplifies the product of an efficient industrial cyclopropanation of a dienol precursor. Serenolide(®) , Toscanol(®) , and Pashminol(®) are other high-impact Δ-fragrance ingredients manufactured at Givaudan. This review describes our journey from advanced SimmonsSmith methodology using Zn carbenoids, to Al- and Mg-mediated cyclopropanation techniques in the context of related alternative cyclopropanation methods for the transfer of the CH2 group onto CC bonds. The resulting cyclopropane products are themselves interesting substrates for further transformation to other flavor and fragrance compounds. Throughout this Review, the notation Δ refers to the presence of a cyclopropane ring, i.e., a 'Δ-compound' is defined as a compound that contains a cyclopropyl substituent or a 'fused cyclopropa' component, or a 'spiro-cyclopropane' moiety.

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