Polymethyleneketene Dimers and Trimers

Erickson, J. L. E.; Collins, Frank E.; Owen, Benny L.

doi:10.1021/jo01340a030

Cited by 41 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the outset, it was assumed that these structural differences should not affect the photochemical properties of these molecules drastically, but that they may affect their packing in the crystal lattice. Spirocyclobutanediones 1a–d were synthesized in one step from commercially available cycloalkylcarboxylic acid chlorides via ketene dimerization in good to moderate yields (71–45%) . The diones 1a–d all displayed highly symmetric 1 H‐NMR and 13 C‐NMR spectra, as well as the characteristic cyclobutanedione 13 C‐NMR carbonyl peak between 210–216 ppm and infrared stretching frequencies from 1734–1736 cm –1 (SI).…”

Section: Resultsmentioning

confidence: 99%

“…Spirocyclobutanediones 1a-d were synthesized in one step from commercially available cycloalkylcarboxylic acid chlorides via ketene dimerization in good to moderate yields (71-45%). [48] The diones 1a-d all displayed highly symmetric 1 H-NMR and 13 C-NMR spectra, as well as the characteristic cyclobutanedione 13 C-NMR carbonyl peak between 210-216ppm and infrared stretching frequencies from 1734-1736cm -1 (SI). Compounds 1a-d formed robust crystals from hexane or ethanol, which were characterized by powder X-ray diffraction, and for 1a, 1c, and a-1d, X-ray crystal structures were determined from suitable crystals grown from hexane.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Ring strain release as a strategy to enable the singlet state photodecarbonylation of crystalline 1,4‐cyclobutanediones

Kuzmanich

2011

J of Physical Organic Chem

View full text Add to dashboard Cite

Challenging most chemists' intuition, highly reactive dialkyl biradicals can be reliably generated in the solid state by taking advantage of the photodecarbonylation of cyclic ketones. However, it has been shown that radical stabilizing groups with resonance‐delocalizing abilities at the α‐carbons of the precursor are required to facilitate the α‐cleavage reaction, and that triplet state reactivity is essential to slow down the combination of the intermediate acyl–alkyl biradical back to the starting ketone. Relatively long triplet acyl–alkyl biradical lifetimes give a chance for the loss of CO to occur. Looking for additional strategies to generate transient biradicals in solids, we studied the solid state photochemistry of four aliphatic, dispiro‐substituted 1,4‐cyclobutandiones (1a–d) that were expected to react from the singlet state. We hypothesized that the release of ring strain from the small ring carbonyl would make the reverse acyl–alkyl combination disfavored, allowing for the loss of CO to occur efficiently and irreversibly. We report here the results of studies carried out in solution, bulk (powder) crystals, and nanocrystalline photochemistry. We have recently shown that excitation of dispirocyclohexyl‐1,3‐cyclobutanedione 1c led to the trapping of the intermediate oxyallyl with a half life of about 42 min. Our studies with the three other crystalline derivatives revealed that, while all react efficiently, the remarkably long lifetime of oxyallyl is unique to crystals of 1c. Copyright © 2011 John Wiley & Sons, Ltd.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Ring strain release as a strategy to enable the singlet state photodecarbonylation of crystalline 1,4‐cyclobutanediones

Kuzmanich

2011

J of Physical Organic Chem

View full text Add to dashboard Cite

show abstract

“…Compounds (I) and (II) were synthesized by condensing the dilithium salt of 3-methylenecyclohexanecarboxylic acid with, respectively, dicyclobutylmethanone (Erickson et al, 1966) and cyclopentanone, following the synthetic sequence reported for the other members of this family of compounds (Carrasco et al, 2001) 7, 18.1, 19.5, 26.2, 26.7, 27.4, 31.9, 32.8, 40.4, 41.1, 44.6, 47.6, 56.9, 67.3, 82.4, 86.4, 176.2; IR (KBr, # max , cm À1 ): 3398,2950,2363,1701,1651,1540,1458,1251,1167,1123,995 7, 24.1, 24.5, 31.7, 31.8, 32.0, 39.2, 40.6, 55.6, 66.4, 82.3, 94.1, 176.0; IR (KBr, # max , cm À1 ): 3749,3380,2956,2870,2361,2337,1703,1456,1339,1257,1157,1046,1002. Single crystals of (I) and (II) suitable for X-ray analysis were grown at room temperature from a damp carbon tetrachloride±2,2,4-trimethylpentane mixture (3:1).…”

Section: Methodsmentioning

confidence: 99%

Supramolecular aggregation of two hydroxycarboxylic acid derivatives

et al. 2005

View full text Add to dashboard Cite

The crystal structures of 7,7-dicyclobutyl-5-hydroxymethyl-6oxabicyclo[3.2.1]octane-1-carboxylic acid, C 17 H 26 O 4 , (I), and 1-(hydroxymethyl)-7-oxaspiro[bicyclo[3.2.1]octane-6,1 H-cyclopentane]-5-carboxylic acid, C 13 H 20 O 4 , (II), determined at 170 K, show that the conformation of the hydroxymethyl group (anti or gauche) affects the dimensionality (one-or twodimensional) of the supramolecular structures via OÐHÁ Á ÁO hydrogen bonds. In (I), the carboxyl and hydroxymethyl groups interact with themselves, forming a one-dimensional stepladder , while in (II), a two-dimensional structure is made up of carboxylic acid centrosymmetric R 2 2 (8) dimers connected by hydroxyl-to-ether contacts. Comment We have reported that compounds possessing axially oriented hydroxyl/carboxylic acid functions might create, by incorporation of water molecules, three-dimensional tubular structures in the crystalline state. Compounds (I) and (II) were considered to be promising candidates, since their respective homologues, (III) and (IV), have been shown to adopt hydrated tubular structures in the solid state (Carrasco et al., 2001). The crystal structures of compounds (I) and (II), reported in this paper, reveal a lack of hydration water molecules, although they were crystallized in a water-saturated atmosphere. To date, compound (IV) is the only one of this series which crystallizes in the anhydrous and hydrated forms in the absence or presence of a water atmosphere, respectively. The molecular structures of compounds (I) and (II) are displayed in Figs. 1 and 2, respectively. In (I), the cyclobutane rings are puckered (Table 1), with dihedral angles of 26.1 (2) (C13/C10/C11 and C11/C12/C13 planes) and 31.7 (1) (C15/ C14/C17 and C15/C16/C17 planes). In both compounds, the oxolane ring presents a distorted 4 T 5 half-chair toward an E 5 envelope conformation, according to the puckering parameters (Cremer & Pople, 1975) and the notation of Giaco-vazzo et al. (1992) for the C1±O1±C9±C5±C6 sequence [9 2 = À50.1 (2) and À51.7 (1) ]. The cyclohexane presents a distorted 1 C 4 towards 1 E conformation [C6±C1±C2±C3±C4± C5; 9 = 0.4 (3) and 1.8 (3) , and = 27.0 (3) and 23.8 (1) ].

show abstract

“…monospiranes (1 and 6), dispiranes (2, 4, 7), trispiranes (3,5,8,9); Chart (1)), the relative positions of the spiro atoms of the same ring (for dispiranes and higher terms) and of the nature (carbocycle or heterocycles) of the constituent six-membered rings.…”

Section: Structure Of Six-membered Ring Spiranes 21 Classificationmentioning

confidence: 99%

“…This type of compounds are named "rotanes" [6,7]. The synthesis, the structural analysis and the reactivity of some rotanes exhibiting central and peripheral six-membered rings have been reported [8,9].…”

Section: Structure Of Six-membered Ring Spiranes 21 Classificationmentioning

confidence: 99%

Six-Membered Ring Spiranes: Carbocycles and Heterocycles with Oxygen

Cismas¹,

Terec²,

Mager³

et al. 2005

COC

View full text Add to dashboard Cite

The data concerning the structure, synthesis and reactivity of six-membered ring spiranes exhibiting carbocycles and heterocycles with oxygen atoms are reviewed. The structural aspects are discussed using specific stereogenic elements and stereochemistry descriptors for spiranes with six-membered rings. The data are supported by high field NMR investigations and molecular structures obtained by X-ray diffractometry. The general procedures and access to spiranes with carbocycles and with heterocycles with oxygen are commented.

show abstract

Polymethyleneketene Dimers and Trimers

Cited by 41 publications

References 0 publications

Ring strain release as a strategy to enable the singlet state photodecarbonylation of crystalline 1,4‐cyclobutanediones

Ring strain release as a strategy to enable the singlet state photodecarbonylation of crystalline 1,4‐cyclobutanediones

Supramolecular aggregation of two hydroxycarboxylic acid derivatives

Six-Membered Ring Spiranes: Carbocycles and Heterocycles with Oxygen

Contact Info

Product

Resources

About