Zur Kenntnis des Kohlenstoffringes. (32. Mitteilung). Über ein ergiebiges Verfahren zur Herstellung von Cyclo‐nonanon

Růžička, L.; Plattner, Pl. A.; Wild, H.

doi:10.1002/hlca.19430260526

Cited by 14 publications

(4 citation statements)

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“…The electronic effect seems to be of secondary importance here, since it has been shown that monohydroboration of 1,2-cyclononadiene (1) with diborane, followed by oxidation, gives mainly cyclonona~lone (5) (I), while dihydroboration of propadiene yields predominantly 1,3-propanediol (5). The formation of a small quantity of cyclic molloolefins (11,12) is in complete agreement with our previous investigation (6), in which we have shown that cyclic allylic organoborane intermediates undergo slow hydrolytic cleavage at the boron-carbon bond under the experimental conditions employed. The formation of 0111~ a iene cis-cyclononene (11) from 1,2-cyclonoi1 d' (I), and a mixture of cis-and trans-cyclotridecelle (12 and 13) containing a major qualltity of trans isomer (13) from 1,2-cyclotridecadiene (2), may be attributed to the thermodynamic stabilities of these cyclic monoolefins (11 and 13) in 9-and 13-membered rings (7).…”

Section: Resultssupporting

confidence: 92%

Hydroboration of cyclic allenes with disiamylborane

Sethi¹,

Joshi²,

Devaprabhakara³

1968

Can. J. Chem.

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It has been shown that 1,2-cyclononadiene and 1,2-cyclotridecadiene undergo 78 and 100% hydroboration respectively, with disiamylborane. 1,2-Cyclononadiene gave products which represented 83 % attack of boron at the central carbon atoll1 and 17 % attack at the terminal carbon atom. I,?-Cyclotridecadiene gave 62 % central carbon attack and 38 % terminal carbon attack. The reactivity and selectivity may be explained mainly in terms of steric effects on a four-centered transition state.Canadian Journal of Chemistry, 46, 2632 (1968 It has been shown that the monohydroboration of 1,2-cyclononadiene (1) with diborane results in the attack of diborane, primarily at the central carbon atom of the allenic linkage (1). The object of the present study was to examine the possibility of stereoselective addition of boron to the allenic linkage with disiamylborane (2), which might have revealed some useful and interesting synthetic routes. In particular we were interested to study the effect of the ring size on the reactivity and selectivity in the direction of addition. Since the monohydroboration of allenes might proceed through monoalkyl-, dialkyl-, and trialkylborane stages, the percentage of electrophilic attacks of diborane on the central and terminal carbon atoms of the allenic linkage, will be governed by the cumulative steric effect due to ring size of the allene and the intermediate organoboranes. The percentage electrophilic attacks of disiamylborane are controlled only by the steric effect of ring size of the allene. Accordingly, we undertook the hydroboration of 1,2-cyclononadiene (1) and 1,2-cyclotridecadiene (2) with disiamylborane which is known to provide greater steric control over diborane (2). Results and DiscussionDisiamylborane was prepared by hydroboration of 2-methyl-2-butene at -5 to -10 "C under a static pressure of nitrogen (3). A solution of the appropriate allene in diglyme was added within 3 min to the above solution. This reaction mixture was left for approximately 3 h to attain room temperature. After stirring for 6 h at room temperature, the mixture was then hydrolyzed until hydrogen was no longer evolved. The product was oxidized with alkaline hydrogen peroxide in the usual manner. The percentage conversion of the allene to products was determined by gas chromatography (4). The results are summarized in Scheme 1.The percentage electrophilic attack of boron on the central and terminal carbon atoms of the allenic linkage, as calculated from the percentage yield of the products and also the percentage conversion of the allenes to products, is shown in Table I.These results suggest that the observed difference in the reactivity and selectivity, in the direction of addition of disiamylborane with 1 ,2-cyclononadiene (1) and 1,2-cyclotridecadiene (2), could be dictated solely by difference in steric requirements of the allenes in the Brown's well known postulated transition state for hydroboration (2). The electronic effect seems to be of secondary importance here, since it has been shown that ...

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Section: Resultssupporting

confidence: 92%

Hydroboration of cyclic allenes with disiamylborane

Sethi¹,

Joshi²,

Devaprabhakara³

1968

Can. J. Chem.

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“…It was suggested that cleavage of the bicyclic ring system of XII during hydrogenation might be possible, owing to strain present in the molecule. It should be noted, however, that XIII or a similar polycyclic compound might arise from XI in view of the nature of the products which cyclooctatetraene forms by Diels-Alder reactions (see pages [126][127][128][129][130][131][132][133]. c. Addition reactions Willstátter and Heidelberger (159) obtained addition products of cyclooctatetraene and chlorine, bromine, and hydrogen bromide but the structures of the products were not known.…”

Section: /^Sch2chomentioning

confidence: 99%

“…Hydrogenation of VIII leads to the formation of appreciable quantities of 1-aminomethylcycloóctanol (X) along with IX (131). Treatment of IX with nitrous acid was reported to lead to ring-enlargement in one case (131) and to the formation of 1-methylcycloóctene (XI) as the main product in another (126). adds two molar equivalents of maleic anhydride quantitatively in the Diels-Alder reaction according to the following scheme (148):…”

Section: E Cyclooctanementioning

confidence: 99%

The Chemistry of Eight-Membered Carbocycles.

Craig¹

1951

Chem. Rev.

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“…[12] In 1943, he reported the first efficient three-steps ynthesis of cyclononanone (8)v ia aT iffenau-Demjanowr earrangement [13] of 1-(aminomethyl)cyclooctan-1-ol (7), itself prepared from cyclooctanone in two steps, upon treatment with sodium nitrite and acetic acid (Scheme 2). [14] In 1947, Prelog and Stoll finally succeeded in developing the first reliable one-step proceduref or the synthesis of mediumsized carbocycles, including nine-membered rings, from dicarboxylic acid esters by acyloin condensation (Scheme 3). [15] De-spite its harsh reaction conditions, this method has become a widelyu sed transformationf or the synthesis of medium-sized rings.…”

Section: Introductionmentioning

confidence: 99%

9‐Membered Carbocycles: Strategies and Tactics for their Synthesis

Huber

Wildermuth

Magauer

2018

Chemistry A European J

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Many natural products comprising a nine-membered carbocyclic core structure exhibit interesting biological effects. However, only a minority have succumbed to their synthesis in the past. The synthesis of functionalized nine-membered carbocycles still remains a challenging goal for synthetic chemists, mainly due to their high ring strain. Different strategies to overcome the unfavorable enthalpic and entropic factors associated with their formation are highlighted in this Concept article. The presented methods are classified into two different categories: (1) the ring-expansion of smaller rings or the ring-contraction of larger rings and (2) the direct cyclization of acyclic precursors.

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Zur Kenntnis des Kohlenstoffringes. (32. Mitteilung). Über ein ergiebiges Verfahren zur Herstellung von Cyclo‐nonanon

Cited by 14 publications

References 4 publications

Hydroboration of cyclic allenes with disiamylborane

Hydroboration of cyclic allenes with disiamylborane

The Chemistry of Eight-Membered Carbocycles.

9‐Membered Carbocycles: Strategies and Tactics for their Synthesis

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