A reasonable accounting for mass spectral stereoisomeric effects in substituted cyclohexanols

Green, Mark M.; Cook, Richard J.; Rayle, W.; Walton, Emily T.; Grostic, Marvin F.

doi:10.1039/c29690000081

Cited by 16 publications

(5 citation statements)

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“…The situation in the 3-hydroxy compounds (11 to 14) is much the same as in the 2-hydroxy derivatives, since only with the a-isomers, which show the higher The a-epimer of the 6-hydroxy compounds (15,16) also exhibits the stronger [M -18]+. peak, as predicted from the availability of hydrogens on tertiary carbons for 1,3-and 1,4-eliminations in this but not in the p-epimer.…”

Section: Alcoholsmentioning

confidence: 91%

“…Pertinent examples demonstrating that ions formed by reactions initiated by a-cleavage are more abundant in the case of the less readily dehydrated epimer are encountered for several epimeric pairs, e.g. the formation of the m/e 153 and 124 ions from the 6-hydroxy epimers (15,16), and the m/e 139 and 140 ions from the 7hydroxy epimers (17, 18, Fig. 1).…”

Section: Alcoholsmentioning

confidence: 99%

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Mass spectrometric studies of diterpenes: VIII—Epimers

Enzell¹,

Wahlberg²,

Gunnarsson³

1974

Org. Mass Spectrom.

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Diterpene epimers differing with respect to orientation of a secondary hydroxyl group, ring fusion or configuration at an asymmetric centre carrying carbon-carbon linked substituents were studied, and certain stereostructural-spectral correlations were achieved for the first two groups. Each of the compounds examined was subjected to multiple scanning at both high and low electron voltage to allow computer assisted statistical calculation and comparison of intensity intervals at a predetermined confidence level for total ion currents and selected peaks.

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Section: Alcoholsmentioning

confidence: 91%

Section: Alcoholsmentioning

confidence: 99%

Mass spectrometric studies of diterpenes: VIII—Epimers

Enzell¹,

Wahlberg²,

Gunnarsson³

1974

Org. Mass Spectrom.

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“…An estimate of the fraction of available energy released in the water elimination reaction of 2-tetra101 can also be estimated using Eqn (6). The AHf of 2-tetra101 is calculated to be -37.4 kcal mol-13' and [CloHlo]' is again assumed to be the 1,2-dihydronaphthalene ion yielding an excess energy of 16 kcal mol-l or less.…”

Section: Water Elimination-2-tetra101mentioning

confidence: 99%

Regiospecificity for water elimination. A mass spectral study of 1‐tetralol and 2‐tetralol

Gross

Chiu

Pokorný

et al. 1977

Org. Mass Spectrom.

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In order to provide a comparison with the extensive research on the mechanism for elimination of water from various cydohexanols, the mass spectra of 1-tetralo1(1,2,3,4-tetrahydro-l-naphthalenol) and 2-tetralol(l,2,3,4-tetrahydro-2-naphthalenol) have been investigated. Deuterium labeling experiments show that the 1-tetralol molecular ion expels water by a highly specific 1,4 elimination, whereas 2-tetra101 undergoes a 1,3 elimination. Both of these processes are competitive with cydoreversion reactions. The ionization potentials and appearance potentials for the major fragments [M-H,O]? and the cycloreversion products have been measured using the Electron Distribution Difference method. In addition, the kinetic energy release in the metastable decompositions to lose water have been measured. It has been found that the 1,4 elimination for 1-tetrdol releases over 50% of the available energy in the transition state, which is unexpected in view of the 6-membering. ring transition state involved. This research also indudes 811 investigation of the nature of the various [CloHlo]* ions formed in the rearrangement reaction to lose water.

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“…Hydrogen scrambling appears not to be significant in water loss from cyclohexanol.22 On balance, therefore, the evidence favors the latter hypothesis, although the reviewers would not ex- to cyclohexanol itself, various alkyl cyclohexanols have been investigated. In the case of 4-tert-butylcyclohexanol, loss of water occurs readily from the trans isomer (10) but to a much smaller extent from the cis Isomer (11) [34][35][36][37] This of course is expected in the light of the results from cyclohexanol itself, since only trans-1,4-fert-butylcyclohexanol (10) could undergo a cis 1,4-elimination of water. It OH has been shown that the hydrogen eliminated with the hydroxyl group is indeed the cis 4-hydrogen.…”

Section: Loss Of Water From Cycloalkanolsmentioning

confidence: 99%