68703-09-3Relevant academic research and scientific papers
Dichotomous stereocontrol in Claisen-Schmidt condensations: Synthesis of a propeller shaped rigid system
Aswathi, C. S.,Nithya, C.,Saumya, T. S.
supporting information, (2021/09/06)
Generally, Claisen-Schimdt condensation produces E-isomers of enones. However, in the Claisen Schimdt condensation between tetrahydropentalene-2,5(1H,3H)-dione and aromatic aldehydes, though initial condensations proceeded with the expected stereochemistry, subsequent condensations, where possible, produced the unexpected Z-isomers.
A rigid bicyclo[3.3.0]octane (octahydropentalene): a heavily constrained novel aliphatic template for molecular self-assembly
Kendhale, Amol M.,Gonnade, Rajesh,Rajamohanan,Sanjayan, Gangadhar J.
, p. 3056 - 3059 (2008/09/20)
This Letter reports the utility of a heavily constrained cis-fused bicyclo[3.3.0]octane (octahydropentalene) aliphatic template for effecting molecular self-assembly. An attractive feature of this system is its heavily constrained alicyclic backbone that would allow for the exploration of self-assembling systems with conformationally ordered features.
General Approach to the Synthesis of Poliquinenes. 8. Synthesis of Triquinacene, 1,10-Dimethyltriquinacene, and 1,10-Cyclohexanotriquinacene
Gupta, Ashok K.,Lannoye, Greg S.,Kubiak, Greg,Schkeryantz, Jeff,Wehrli, Suzanne,Cook, James M.
, p. 2169 - 2179 (2007/10/02)
The synthesis of tricyclo4,10>deca-2,5,8-triene (1), 1,10-dimethyltricyclo4,10>deca-2,5,8-triene (3), and tetracyclo1,8.04,8>tetradeca-2,5,13-triene (4) has been accomplished via the reaction of 1,2-dicarbonyl compounds with di-tert-butyl 3-oxoglutarate (Weiss reaction).Condensation of glyoxal 5a with di-tert-butyl 3-oxoglutarate (6b) gave the tetra-tert-butyl cis-dioxobicyclooctane-2,4,6,8-tetracarboxylate 7b in 93percent yield.This bisenol 7b was converted into the bisenol ether 9b regiospecifically (90percent yield).This transformation was followed by monoalkylation (KH, allyl iodide; -58 deg C) and hydrolysis to generate 2-allyl-cis-bicyclooctane-3,7-dione in 90percent overall yield from 9b.The mixture of epimiric 2-allyl-3,7-diones 11a,b was transformed (O3; DMS) into the mixture of epimiric aldehydes 12a,b.This process was followed by aldol cyclization (2 N HCl, THF) to provide the diastereomeric mixture of of endo-(13a) and exo-(13b) triquinane monols in 85percent yield.Reduction of 13a,b with borane-THF (0 deg C) generated the stereoisomeric mixture of triols 14a,b which were subjected to an HPMA-mediated dehydration sequence to provide triquinacene (1), accompanied by small amounts of isotriquinacene.The mixture of trienes were converted into pure 1 by exposure to p-TSA in methylene chloride-pentane.Substitution of biacetyl (5b) for glyoxal 5a in the Weiss reaction, followed by the analogous steps detailed in the synthesis of 1, provided 1,10-dimethyltriquinacene (3).In addition, the synthesis of 1,10-cyclohexanotriquinacene (4), another centro-substituted triquinacene, has been accomplished by substitution of cyclohexane-1,2-dione (23) for 5a in the condensation, followed by the same sequence of reactions presented above for 1 and 3.
General Approach to the Synthesis of Polyquinenes via the Weiss Reaction. 6. Progress toward the Synthesis of Dicyclopentapentalenes
Lannoye, G.,Sambasivarao, Kotha,Wehrli, S.,Cook, J. M.,Weiss, U.
, p. 2327 - 2340 (2007/10/02)
The synthesis of the three tetraquinanes tetracyclo4,11.06,10>dodecanetetraol (27), tetracyclo2,6.09,13>tetradecanediol (36), and tetracyclo2,6.010,14>tetradecanediol (39) has been achieved via the Weiss reaction.Reaction of glyoxal (4a) with di-tert-butyl 3-oxoglutarate (5b) gave tetra-tert-butyl 3,7-dioxo-cis-bicyclooctane-2,4,6,8-tetracarboxylate (6b) in excellent yield.This was converted, regiospecifically, into bisenol ether 20b with diazomethane.The bisalkyllation of 20b was effected with allyl iodide/KH to provide a mixture of the 2,6-diallyl regioisomer 23b (64percent) and the corresponding 2,8-diallyl dione 24b (36percent); the former compoud crystallized from the reaction mixture.Hydrolysis of teraester 23b furnished 2,6-diallyl dione 7, which was oxidized and cyclized to diketo diol 26, isolated as a mixture of diexo and diendo stereoisomers 26a and 26b, both of which were reduced with borane-tetrahydrofuran to provide the desired tetraol 27 in 80percent yield.The HMPA-mediated dehydration of 27 gave the tetracyclotetradecadiene 28.Furthermore, the 2,6-diallyl diones 7a and 7b were converted with HBr-peroxides into dibromides 35a,b, and this mixture of epimers was cyclized to the tetracyclotetradecanediol 36 on stirring with samarium diiodide (80percent yield).Analogous to the chemistry developed for preparation of 36, the 2,8-diallyl tetra-tert-butyl ester 24b was converted into the 2,8-bis(3-bromopropyl) dione 38, which cyclized on treatment with SmI2 to the desired tetracyclic tetradecanediol 39 in 69percent yield.
REACTION OF DIMETHYL SODIO-3-KETOGLUTARATE WITH GLYOXAL AND SUBSTITUTED GLYOXALS; FIRST EXPEDITIOUS PREPARATION OF BICYCLOOCTANE-3,7-DIONE; SYNTHESIS AND CRYSTAL STRUCTURE OF 5,7-DIHYDROXY-4-METHOXYCARBONYL-3-PHENYL-1-INDANONE
Bertz, Steven H.,Rihs, G.,Woodward, R.B.
, p. 63 - 70 (2007/10/02)
A simple and efficient two-step preparation of bicyclooctane-3,7-dione starting from the sodium enolate of dimethyl 3-ketoglutarate and glyoxal is described.This is an unprecedented case in which a condensation reaction of glyoxal is more successful under vigorous conditions (refluxing methanol) than under much milder ones (buffered water at ambient temperature).The major product (after hydrolysis-decarboxylation) from the analogous sequence with phenylglyoxal is 5,7-dihydroxy-4-methoxycarbonyl-3-phenyl-1-indanone, the result of a Dieckmann reaction in addition to the Michael and aldol reactions.Only the latter two occur in aqueous buffers, where the product after hydrolysis-decarboxylation is 1-phenylbicyclooctane-3,7-dione.The X-ray crystal structure of the indanone reveals a novel hydrogen bonding phenomenon.
Bicycloocta-1,5-diene-3,7-dione
Docken, Adrian M.
, p. 4096 - 4097 (2007/10/02)
Bicycloocta-1,5-diene-3,7-dione (5) has been prepared by the hydrolysis-decarboxylation of tetramethyl 3-hydroxy-7-oxobicycloocta-1,3,5-triene-2,4,6,8-tetracarboxylate sodium salt (2), which was obtained in one step from "Vossen's Red Salt" (1).
2,5-Bis(methoxycarbonyl)-4-hydroxycyclopent-2-en-1-one as an Intermediate in Weiss' Glyoxal Reaction. Analogous Chemistry of Malondialdehyde
Bertz, Steven H.,Adams, William O.,Silverton, J. V.
, p. 2828 - 2830 (2007/10/02)
Glyoxal and dimethyl 3-oxoglutarate condense at pH nonane-2,4,6,8-tetracarboxylate.
