ChemInform Abstract: Ring Inversion in 5,5‐Disubstituted 1,3‐Dioxanes.

Bochkor, S. A.; Lapuka, L. F.; Kurmaeva, E. S.; Chalova, O. B.; Злотский, С. С.; Rakhmankulov, D. L.

doi:10.1002/chin.198750225

ChemInform

1987

DOI: 10.1002/chin.198750225

|View full text |Cite

ChemInform Abstract: Ring Inversion in 5,5‐Disubstituted 1,3‐Dioxanes.

S. A. Bochkor¹,

L. F. Lapuka²,

E. S. Kurmaeva³

et al.

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2011

Publication Types

Select...

Article1

Relationship

Self Cite0

Independent1

Authors

Journals

Cited by 1 publication

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The chlorine atoms therein are relatively readily replaced by iodine with formation of mono-and diiodo derivatives; this process is stereoselective, and chlorine atom is replaced preferentially in the equatorial chloromethyl substituent [4]. Conformational behavior of 5,5-bis(halomethyl)-1,3-dioxanes having no substituent on C 2 at room temperature is characterized by fast (on the NMR time scale) ring inversion [5]. By contrast, molecules of 2-substituted analogs exist mainly as chair conformers with equatorial orientation of the substituent on C 2 (C eq ) [6,7].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Conformational analysis of 2-substituted 5,5-bis(chloromethyl)-1,3-dioxanes

2011

View full text Add to dashboard Cite

Quantum-chemical study on stationary points on the potential energy surfaces of 2-alkyl-, 2-phenyl-, and 2-methyl-2-phenyl-5,5-bis(chloromethyl)-1,3-dioxanes in terms of HF/6-31G(d), B3PW91/6-31G(d,p), and B3PW91/LanL2Dz nonempirical approximations revealed only one pathway for conformational isomerization of the equatorial and axial chair conformers through intermediate energy minimum corresponding to the 2,5-twist conformer. I, R = H, R′ = Me; II, R = H, R′ = i-Bu; III, R = H, R′ = Ph; IV, R = Me, R′ = Ph.Interest in structural studies on 1,3-dioxanes is determined by specificity of their structure and by the use of these compounds as reagents in fine organic synthesis [1-3]. 5,5-Bis(chloromethyl)-1,3-dioxanes occupy a specific place among cyclic acetals. The chlorine atoms therein are relatively readily replaced by iodine with formation of mono-and diiodo derivatives; this process is stereoselective, and chlorine atom is replaced preferentially in the equatorial chloromethyl substituent [4]. Conformational behavior of 5,5-bis(halomethyl)-1,3-dioxanes having no substituent on C 2 at room temperature is characterized by fast (on the NMR time scale) ring inversion [5]. By contrast, molecules of 2-substituted analogs exist mainly as chair conformers with equatorial orientation of the substituent on C 2 (C eq ) [6, 7]. According to the X-ray diffraction data, 5,5-bis(chloromethyl)-2-phenyl-1,3-dioxane in crystal has chair structure with the phenyl group occupying equatorial position [6]. In the recent years, computer simulation of conformational transformations of various molecular systems, in particular of cyclic acetals, attracts increasing attention [8]. In the present work we examined conformational isomerization pathways of 2-methyl-, 2-isobutyl-, 2-phenyl-, and 2-methyl-2-phenyl-5,5-bis(chloromethyl)-1,3-dioxanes I-IV in terms of HF/6-31G(d), B3PW91/6-31G(d,p), and B3PW91/LanL2Dz quantum-chemical approximations using GAMESS software package [9].In the first step we estimated the relative energies of conformers differing by mutual orientation of chlorine atoms in the chloromethyl substituents. For this purpose, the energies of four possible chair conformers A-D of compounds I-III with equatorial orientation of the substituent on C 2 were calculated at the B3PW91/6-31G(d,p) level of theory. In keeping with the X-ray diffraction data [6], the most stable is conformer A with gauche orientation of the chloromethyl groups (Table 1). This structure occupies the global

show abstract

mentioning

confidence: 99%

“…2). EXPERIMENTAL 1,3-Dioxanes I-IV were described previously [4][5][6]. Conformational isomerizations of compounds I-IV were simulated by optimizing geometric parameters of their molecules upon variation of torsion angles OCCC and OCOC within ±50°.…”

mentioning

confidence: 99%

Conformational analysis of 2-substituted 5,5-bis(chloromethyl)-1,3-dioxanes

2011

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

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

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.

ChemInform Abstract: Ring Inversion in 5,5‐Disubstituted 1,3‐Dioxanes.

Cited by 1 publication

References 0 publications

Conformational analysis of 2-substituted 5,5-bis(chloromethyl)-1,3-dioxanes

Conformational analysis of 2-substituted 5,5-bis(chloromethyl)-1,3-dioxanes

Contact Info

Product

Resources

About