176-91-0Relevant academic research and scientific papers
Trianion synthon approach to spirocyclic heterocycles
Perry, Matthew A.,Hill, Richard R.,Rychnovsky, Scott D.
supporting information, p. 2226 - 2229 (2013/06/05)
A variety of spirocyclic heterocycles have been constructed by a double-alkylation and reductive cyclization approach utilizing α-heteroatom nitriles as trianion synthons. The method provides access to heteroatom-substituted spirocycles in a variety of ring sizes that are found in natural products and are important in pharmaceutical lead development and optimization.
General Synthesis of 1-Oxaspirodecan-2-ones and 1-Oxaspirodecanes from 5-Methylene-2(5H)-furanone
Alonso, Daniel,Font, Josep,Ortuno, Rosa M.
, p. 5567 - 5572 (2007/10/02)
5-Methylene-2(5H)-furanone underwent Diels-Alder cycloadditions to butadiene and several acyclic and cyclic C-substituted dienes, respectively, affording bicyclic and tricyclic spiroadducts in good yields.These compounds are precursors of other unsaturated and saturated spirolactones and also spiroethers, which were obtained through simple chemical reactions, i.e., hydrogenation of C-C double bonds, reduction of the carbonyl group, and Michael addition.The synthesis of 32 spirolactones and eight spiroethers illustrates the scope and efficiency of this method.Many of these products are suitable for use as components of perfumes and aromas owing to their olfactive properties.
γ-Lithioalkoxides via Reductive Lithiation of Oxetanes by Aromatic Radical Anions
Mudryk, Boguslaw,Cohen, Theodore
, p. 5657 - 5659 (2007/10/02)
Oxetanes are cleaved at 0 deg C in tetrahydrofuran by lithium 4,4'-di-tert-butylbiphenylide, giving lithium γ-lithioalkoxides which can provide 2-substituted tetrahydrofurans by trapping with aldehydes and ketones followed by acid cyclization of the resulting 1,4-diols; the cuprates of these dianions undergo conjugate addition and nucleophilic substitution reactions.
Synthetic and Stereochemical Studies of the Octahydro-1-benzopyran System
Griffiths, D. Vaughan,Wilcox, Geoffrey
, p. 431 - 436 (2007/10/02)
The cis and trans isomers of the octahydro-1-benzopyran system have been synthesised and their conformations studied by low-temperature (13)C and highfield (1)H n.m.r. spectroscopy.The position of the conformational equilibrium in the cis isomer at -70 deg C in CDCl3-CFCl3 (50:50) has been determined as approximately 99.5:0.5 (ΔG0 -8.9 kJ mol-1) in favour of the conformation having the oxygen axially disposed towards the cyclohexane ring.
One-Step Annelation. A Convenient Method for the Preparation of Diols, Spirolactones, and Spiroethers from Lactones
Canonne, Persephone,Foscolos, Georges B.,Belanger, Denis
, p. 1828 - 1835 (2007/10/02)
1-(ω-Hydroxyalkyl)cyclopentanols and -cyclohexanols were prepared in one step in high yields from butane-1,4-diyl- and pentane-1,5-diylmagnesium dibromides and lactones in tetrahydrofuran.This method was found to be general and applicable to lactones of any size (β, γ, δ, and ε) and structure whether aliphatic, aromatic, bicyclic, or spirocyclic.Evidently important steric hindrance close to the carbonyl group prevents annelation and attack on the second nucleophilic center of the Grignard reagent.Furthermore, in the case of oxetan-2-one one obtains, in additionto the corresponding diol, products resulting from scission of the C-O bond.The diols by appropriate transformation afford new routes to spirolactones and spiroethers.
