Progress in the Synthesis and Transformations of Alkylidenecyclopropanes and Alkylidenecyclobutanes

Brandi, Alberto; Cicchi, Stefano; Cordero, Franca M.; Goti, Andrea

doi:10.1021/cr400686j

Cited by 243 publications

(83 citation statements)

References 729 publications

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“…Furthermore, cyclopropane rings bearing an electron-withdrawing group can readily undergo a ring-opening reaction 32 – 34 , further highlighting the difficulties of this approach. On the basis of these issues, we envisioned that the use of alkylidenecyclopropane 35 as an appropriate intermediate would avoid an unwanted ring-opening reaction and the formation of a caged structure. We also envisioned that avenaol could be obtained from 2 by the dihydroxylation of its convex face and the introduction of the D ring (Fig.…”

Section: Resultsmentioning

confidence: 99%

Total synthesis of avenaol

et al. 2017

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Avenaol, isolated from the allelopathic plant black oat, was the first C20 germination stimulant related to strigolactones. Structurally, it consisted of a bicyclo[4.1.0]heptanone skeleton containing a cyclopropane ring bearing three main chains projecting in the same direction (i.e. all-cis-substituted cyclopropane). Herein, we report the total synthesis of avenaol using a robust strategy involving the formation of an all-cis-substituted cyclopropane via an alkylidenecyclopropane. The key factors in the success of this total synthesis include the Rh-catalysed intramolecular cyclopropanation of an allene, an Ir-catalysed stereoselective double-bond isomerisation, and the differentiation of two hydroxymethyl groups via the regioselective formation and oxidation of a tetrahydropyran based on the reactivity of a cyclopropyl group. This strategy effectively avoids the undesired ring opening of the cyclopropane ring and the formation of a caged structure. Furthermore, this study confirms the proposed structure of avenaol, including its unique all-cis-substituted cyclopropane moiety.

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Section: Resultsmentioning

confidence: 99%

Total synthesis of avenaol

et al. 2017

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“…Surprisingly, from cyclobutanone 7 and sulfones 2b, the reaction did not reach completion even after stirring for 18 h. Although pyrrolidino-oxetane derivative 5d obtained from pyrrolidinosulfone 3 was unstable, analogues 6d and 7d were isolated in good yields. To access vinyl sulfones to act as Michael acceptors, a HornerWadsworth-Emmons reaction was realized with phosphonosulfone 4 in the presence of NEt 3 and LiCl in tetrahydrofuran (THF) at 20°C. [36] The reaction of sulfone 4 with oxetanone 5 led to corresponding vinyl sulfone 5e in 84 % yield.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Fluorine‐Containing 3,3‐Disubstituted Oxetanes and Alkylidene Oxetanes

et al. 2015

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“…Interesting ring opening/N−O cleavage transformations are known for 5‐spiro substituted isoxazolidines of type 79 (Scheme ). Reviews on this topic are available in the literature . Therefore, we mention only some main aspects.…”

Section: Transformations Of Small Ring Annelated Isoxazolidinesmentioning

confidence: 99%

“…Reviews on this topic are available in the literature. [63][64][65] Therefore,w em ention only some main aspects.Ofspecial concern is the regioselectivity of cycloadditions of MCP 74 and N-oxides 78, [66,67] since4 -spiro adducts 80 are incapable of the described rearrangement. Thet ransformationsu sually require high temperatures (up to flash vacuum thermolysis)a nd the suggested initial homolytic NÀOb ond cleavage is supported by quantum calculations.…”

Section: Transformations Of 5-spiro Small Ring Substituted Isoxazolidmentioning

confidence: 99%

Small Ring Compounds and N‐oxides: Cycloadditions and Related Processes

Tabolin

Ioffe

2016

Israel Journal of Chemistry

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The review discusses the possibilities for reactions of small ring compounds (cyclopropanes, cyclobutanes, and their heteroanalogs) with various N‐oxides (nitrones, nitronates, nitrile oxides, etc.). Two major paths include: formal cycloadditions of small cycles with N‐oxide possessing dipoles, and [3+2] cycloadditions of small cyclic alkenes with N‐oxides, followed by N−O bond cleavage‐assisted rearrangement/ring opening.

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Progress in the Synthesis and Transformations of Alkylidenecyclopropanes and Alkylidenecyclobutanes

Cited by 243 publications

References 729 publications

Total synthesis of avenaol

Total synthesis of avenaol

Synthesis of Fluorine‐Containing 3,3‐Disubstituted Oxetanes and Alkylidene Oxetanes

Small Ring Compounds and N‐oxides: Cycloadditions and Related Processes

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