Long range phenomena. V (1): Stereo‐specific long range coupling 4J, involving tert. Methyl groups

Use of the NOE (Nuclear Overhauser Effect) made a choice possible between the cis-trans isomers A and E of the ethylesters of 3-ethyl-3-pentenoic acid. It was found that for both isomers 5J;. ", ;.(homoallylic coupling) is more important than 5Jc,'.t,,. while to the contrary 4J:rfty (allylic c.) < "J',ff. . Some other possible criteria for cis-trans assignations are discussed. The conclusions are corroborated by the spectrum of the isomeric 3-ethyl-2-pentenoate (C).Dehydration of the Reformatsky product I affords three compounds: A, B, and C.

show abstract

Long Range Phenomena VI [1] CIS‐ and Trans‐Isomers of Ethylheptenoates

Anteunis

Bruyn²,

Pooter³

et al. 1968

Bulletin des Soc Chimique

View full text Add to dashboard Cite

show abstract

Long Range Phenomena VII [1] Atypical Long Range Paths in 1,3‐Thioxanes and 1,3‐Dithianes

Gelan¹,

Anteunis²

1968

Bulletin des Soc Chimique

Self Cite

View full text Add to dashboard Cite

LONG RANGE PHENOMENA V11 [I] ATYPICAL LONG RANGE PATHS IN I,3-THIOXANES A N D 1,3-DITHIANES J . GELAN and M. ANTEUNISAnalogous long range phenomena as observed in 1,3-dioxanes [2-4] are found in 1,3-thioxanes and 1,3-dithianes. Coupling through oxygen is much less than through sulphur in 1,3-thioxanes. This is of great help in structure elucidation of I ,3-thioxane derivatives. The special conformation of this ring can be at the basis of this observation. The easy distortion of the ring of the sulphur analogs of 1,3-dioxanes is illustrated by the fact that the occurrenceof these long range phenomena depends strongly of the degree and nature of substitution. " Classical " (planar zig-zag) " anomalous " paths J2e,4e = 1.0-1.5* J2e,4n = 0.5* J2e,5e = 0.9* J 2~, 5 a = 0 J2o,4e = 0.4 J$n,6a = ON'*) J40,6p = 0.5(5*) J2a,4a = 0.3 448 J. Gelan and M. AnteunisIn contrast, the peaks belonging to H-2e, as a rule, are enlarged, or even multiple (J2 e,4e and/or J, e,5 and/or J, e,4a). As the (nonkxistence of long range phenomena depends in a subtile manner on the geometry of the bond-path followed, it was interesting to look at the 1,3-thioxane (11) and 1,3-dithiane ring (III). It has been found that the switch from 0 to S generally causes an increase of the " atypical " (non-straight zip-zag) coupling constants.

show abstract

The Stereochemical Requirements for Long Range Coupling Between Protons in α‐Halocyclohexanones

Jefford

Waegell

1970

Bulletin des Soc Chimique

View full text Add to dashboard Cite

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Long range phenomena. V (¹): Stereo‐specific long range coupling ⁴J, involving tert. Methyl groups

Cited by 16 publications

References 3 publications

Long Range Phenomena VI [1] CIS‐ and Trans‐Isomers of Ethylheptenoates

Long Range Phenomena VI [1] CIS‐ and Trans‐Isomers of Ethylheptenoates

Long Range Phenomena VII [1] Atypical Long Range Paths in 1,3‐Thioxanes and 1,3‐Dithianes

The Stereochemical Requirements for Long Range Coupling Between Protons in α‐Halocyclohexanones

Contact Info

Product

Resources

About