Bromination and acetylation of the isomeric cyclooctadienes

Moon, Sung; Ganz, Charles R.

doi:10.1021/jo00830a001

Cited by 20 publications

(7 citation statements)

References 3 publications

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“…When purification of compounds 4a − c was attempted by distillation rather than by standard chromatographic purification, most of the substance isomerized and the corresponding new 4‐alkyl‐2,6‐cyclooctadien‐1‐ones 7a − c were obtained with high yields. It is known that 2,4‐cyclooctadien‐1‐ol thermally rearranges into cycloocta‐3‐en‐1‐one by a 1,5‐hydrogen shift 21. Furthermore, the formation of racemic 4‐ tert ‐butylcycloocta‐2,6‐diene‐1‐one by the reaction of t BuLi with COT monoepoxide and subsequent distillation has been described, albeit without the isolation of the intermediate 4‐ tert ‐butyl‐2,5,7‐cyclooctatriene‐1‐ol 22.…”

Section: Resultsmentioning

confidence: 99%

Simple Synthetic Transformations of Highly Enantio‐Enriched 4‐Alkyl‐2,5,7‐cyclooctatrienols into Functionalized Bicyclo[4.2.0]octa‐2,4‐dienes and 2,6‐Cyclooctadienones

et al. 2004

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4‐Alkyl‐2,5,7‐cyclooctatrienols with high enantiomeric purities (93−96% ee), obtained by an improved copper‐phosphoramidite‐catalyzed addition of dialkylzinc reagents to cyclooctatetraene monoepoxide, have been subjected to simple and practical manipulations. Simple esterification reactions are able to deliver new functionalized isomeric 8‐alkyl‐7‐acyloxybicyclo[4.2.0]octa‐2,4‐dienes through a domino sequence of rearrangement reactions, in good yields. Moreover, new 4‐alkyl‐substituted‐2,6‐cyclooctadienones with high optical purity can be efficiently obtained from gram‐scale reactions by simple thermal treatment. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

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Section: Resultsmentioning

confidence: 99%

Simple Synthetic Transformations of Highly Enantio‐Enriched 4‐Alkyl‐2,5,7‐cyclooctatrienols into Functionalized Bicyclo[4.2.0]octa‐2,4‐dienes and 2,6‐Cyclooctadienones

et al. 2004

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“…For every Table I1 compound for which the necessary basis compounds were available, predicted chemical shifts of each nonheteroatom-substituted sp3 carbon were calculated assuming strict additivity of A S values. For example, the predicted shift of 31.0 ppm (observed, 31.2) for carbon 6 in alcohol 20 was obtained by adding the requisite A S values from endo-cis-bicyclo[3.3.0]octan-2-ol(2, -4.9) and cis-bicyclo[3.3.0]oct-2-ene (4, +1.7) to 34.2 ppm (the chemical shift of C-2 in the parent hydrocarbon 1). For each compound thus examined, we have calculated the average of the absolute values of the errors (IEl) and the correlation factor R;3 this information is compiled in Table 111.…”

Section: Discussionmentioning

confidence: 99%

Carbon-13 chemical shifts in bicyclo[3.3.0]octanes

Whitesell¹,

Matthews²

1977

J. Org. Chem.

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From a detailed analysis of the carbon-13 spectral data of 52 bicyclo[3.3.0]octanes a set of substituent effects was derived from the monosubstituted compounds. Using the shift change values (AS) from this basis set, it is possible to accurately predict chemical shifts for polyfunctionalized bicyclo[3.3.0]octanes. These predictions, used in conjunction with statistical tools (IEl and R values), permit regio-and stereochemical analysis of new bicyclo[3.3.0] derivatives.

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“…All solvents were dried by standard methods, distilled and deoxygenated before use. The compound [W(CO) 3 (g 6 -C 7 H 8 )] [23] and bromocyclooctadienes [24,25] were prepared by published procedures. Silica for column chromatography (70-230 mesh) was purchased from Lancaster Synthesis and HBF 4 (as a 54 wt% solution in diethyl ether) was supplied by Aldrich.…”

Section: General Proceduresmentioning

confidence: 99%