A very large stereoelectronic effect on acetal cleavage

Evans, Christopher M.; Glenn, Robert; Kirby, Anthony J.

doi:10.1021/ja00381a047

Cited by 7 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although it has been previously shown in rigid, bicyclic systems that the orientation of the oxygen lone pair relative to the protonated oxygen leaving group has a substantial effect on the stability of an acetal to hydrolysis, [7] to the best of our knowledge there are no such reports on the effects of ring-size in such hydrolyses. As discussed above, it appears that the conformation of the acetal ring is certainly an important factor in governing the observed reaction rates and therefore, stereoelectronic effects are the underlying major controlling influences that result from a combination of ring size, conformational and acetal substituents.…”

Section: Resultsmentioning

confidence: 75%

The Effects of Ring Size and Substituents on the Rates of Acid‐Catalysed Hydrolysis of Five‐ and Six‐Membered Ring Cyclic Ketone Acetals

Knowles

Whiting

2007

Eur J Org Chem

View full text Add to dashboard Cite

A series of sterically similar five‐ and six‐membered ring cyclic diol‐derived ketone acetals have been prepared and their rates of acid‐catalysed hydrolysis examined. The rates of hydrolysis are substantially affected by acetal ring conformational stereoelectronic effects and resonance effects depending upon the substituents on the parent ketone; an A1 mechanism of hydrolysis explains the observed effects.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

show abstract

Section: Resultsmentioning

confidence: 75%

The Effects of Ring Size and Substituents on the Rates of Acid‐Catalysed Hydrolysis of Five‐ and Six‐Membered Ring Cyclic Ketone Acetals

Knowles

Whiting

2007

Eur J Org Chem

View full text Add to dashboard Cite

show abstract

“…For example, it has been reported that the kinetics of acetal cleavage is influenced by the anomeric effect that makes the hydrolysis faster. [29][30][31] Put simply, the interaction of the electron lone pair of heteroatom and the anti-bonding orbital is the driving force for the C-X bond cleavage.…”

Section: ∑ (3)mentioning

confidence: 99%

Stereoelectronic Effects: A Powerful Concept in Explaining Kinetic and Thermodynamic Aspects of Retro Cheletropic Reactions

Sabet‐Sarvestani

Izadyar²,

Bakavoli

et al. 2015

Journal of Chemical Research

View full text Add to dashboard Cite

Kinetic and thermodynamic aspects of the retro cheletropic reaction of sulfur dioxide extrusion have been investigated. The interaction of the X–S bond (X=NH, S, O and CH2) and oxygen lone pairs of SO2 showed remarkable stereoelectronic effects and its correlation with the difference between computed and empirical bond length (Δl) have been analysed. The facility of the reaction in the case of four derivatives (X=NH, S, O and CH2) has been investigated from the viewpoint of product delocalisation energy. In addition, substitution effects have been studied on the relative Gibbs free energy of reaction for the oxygen derivative (X=O). Moreover, a correlation has been found between the Gibbs free energy of reaction in the presence of the substituent and Δl as a criterion for the value of the interaction between the X–S bond and oxygen lone pairs of the SO2 group. Finally, a new method based on electron density has been used for evaluation of the synchronicity values of the reaction. According to the corresponding diagrams, the calculated synchronicity values of the Wiberg bond indices and electron density are in good agreement.

show abstract

“…As long as their conformation is fixed, the equatorial compounds are very stable (Evans et al, 1982), and it is possible to prepare acetal derivatives with highly electronegative exocyclic oxygen groups. In this paper we report the crystal and molecular structure of the phosphate ester (2), which has a very good [(PhO) 2 PC>2 ] leaving group at the acetal centre, prevented from leaving by the stereoelectronic barrier imposed by the fixed geometry of the [3.3.1]bicyclononane system (Kirby, 1982).…”

Section: Introductionmentioning

confidence: 99%

The crystal structure of 9-oxabicyclo[3.3.1]non-1-yl diphenyl phosphate

Jones¹,

Sheldrick²,

Kirby³

et al. 1983

Zeitschrift Für Kristallographie - Crystalline Materials

Self Cite

View full text Add to dashboard Cite

The structure of the title compound (2) has been determined [PI, a = 11.792(3), b = 12.448(3), c = 15.686(5) Â, α = 95.58(2), β = 109.08(2), y = 116.59(2)°, Ζ = 4, R = 0.047]. There are two molecules in the asymmetric unit, differing mainly in the torsion angles at the phosphate groups (maximum difference ca. 5 °). C(5) -0(9), the C -O bond antiperiplanar to the bond to the phosphate leaving group, is in both molecules appreciably longer than in related acetals with poorer leaving groups. This is part of a trend consistent with the orbital-orbital interaction known as σ-conjugation. The expected shortening of the endocyclic CO -C(OX) bond [here C(l) -0(9)] is however not clearly established.

show abstract

A very large stereoelectronic effect on acetal cleavage

Cited by 7 publications

References 2 publications

The Effects of Ring Size and Substituents on the Rates of Acid‐Catalysed Hydrolysis of Five‐ and Six‐Membered Ring Cyclic Ketone Acetals

The Effects of Ring Size and Substituents on the Rates of Acid‐Catalysed Hydrolysis of Five‐ and Six‐Membered Ring Cyclic Ketone Acetals

Stereoelectronic Effects: A Powerful Concept in Explaining Kinetic and Thermodynamic Aspects of Retro Cheletropic Reactions

The crystal structure of 9-oxabicyclo[3.3.1]non-1-yl diphenyl phosphate

Contact Info

Product

Resources

About