61586-79-6Relevant academic research and scientific papers
A Formal Synthesis of Ptaquilosin. The Aglycon of a Potent Bracken Carcinogen Ptaquiloside
Cossy, Janine,Ibhi, Said,Kahn, Philippe H.,Tacchini, Laura
, p. 7877 - 7880 (1995)
A formal synthesis of racemic and optically active ptaquilosin has been achieved from the commercially available methyl 2-oxocyclopentanecarboxylate.
Formal total synthesis of (?)-hamigeran B from a chemo-enzymatically prepared building block with quaternary chiral center
Kuwata, Kazuaki,Fujita, Rie,Hanaya, Kengo,Higashibayashi, Shuhei,Sugai, Takeshi
, p. 740 - 745 (2018)
A formal total synthesis of (?)-hamigeran B was achieved in 17 steps from commercially available ethyl 2-oxocyclopentanecarboxylate. Carbonyl reductase-catalyzed asymmetric reduction and the subsequent chemical transformations furnished an enantiomerically pure synthetic intermediate, (R)-5-formyl-2-isopropyl-5-methylcyclopent-1-en-1-yl trifluoromethylsulfonate. Suzuki-Miyaura coupling with Gao's arylboronate [2-(2-formyl-3-methoxy-5-methylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane], under PdCl2(dppf)?CH2Cl2 catalysis, and the subsequent cyclization by way of intramolecular reductive SmI2-mediated 1,2-diol formation provided a tricyclic skeleton with a tetrasubstituted double bond between C-1 and C-9b. Upon hydrogenation of this double bond, the proper stereochemistry of the remaining chiral centers was established. Exclusive addition of the hydrogen atom from the β-face occurred, owing to the shielding of the α-face with a bulky TBS protective group on the C-4 alcohol. The hydrogenation products were transformed into Clive's synthetic precursor for (?)-hamigeran B.
Is the ring conformation the most critical parameter in lipase-catalysed acylation of cycloalkanols?
Levy, Laura M.,Lavandera, Ivan,Gotor, Vicente
, p. 2572 - 2577 (2004)
CAL-B catalysed the resolution of several five and six-membered cyclic β-hydroxy esters efficiently with the exception of the cis-cyclohexanol (±)-4. When employing molecular modelling techniques the conformation turned out to be the most important determ
Investigation of Electrostatic Interactions towards Controlling Silylation-Based Kinetic Resolutions
Zhang, Tian,Redden, Brandon K.,Wiskur, Sheryl L.
supporting information, p. 4827 - 4831 (2019/08/12)
Electrostatic interactions between a silylated isothiourea intermediate and an ester π system were explored by determining how variations in sterics and electronics affect the selectivity of a silylation-based kinetic resolution. Sterics on the π systems affect the selectivity factors of alkyl 2-hydroxycyclohexanecarboxylates, resulting in a strong correlation of selectivity factors to Charton values. Induction effects of electron-withdrawing substituents on phenyl esters significantly enhance selectivity supporting an edge to face π–π interaction. The linear free energy relationships that were uncovered will aid in future incorporation of intermolecular electrostatic interactions towards controlling asymmetric reactions.
Copper-catalyzed, stereoconvergent,: Cis -diastereoselective borylative cyclization of ω -mesylate- α, β -unsaturated esters and ketones
Zuo, Ya-Jie,Chang, Xiao-Tong,Hao, Zhi-Ming,Zhong, Chong-Min
, p. 6323 - 6327 (2017/08/10)
The Cu(i)-catalyzed stereoconvergent borylative cyclization of ω-mesylate-α,β-unsaturated compounds is facilitated by a simple Cu-bisphosphine catalyst. This reaction provides a novel route to cis-β-boron-substituted five- and six-membered carbocycle and heterocycle esters. Mechanistic studies indicate that stereoconvergence and cis-substitution likely stem from the rapid enolation of the borylcopper adduct with the substrate double bond and the formation of a five-membered intermediate, respectively.
Chemo-enzymatic synthesis of (R)-5-hydroxymethyl-2-isopropyl-5-methylcyclopent-1-en-1-yl trifluoromethylsulfonate, a potential chiral building block for multicyclic terpenoids
Kuwata, Kazuaki,Hanaya, Kengo,Sugai, Takeshi,Shoji, Mitsuru
, p. 964 - 968 (2017/07/11)
The chemo-enzymatic synthesis of (R)-5-hydroxymethyl-2-isopropyl-5-methylcyclopent-1-en-1-yl trifluoromethylsulfonate, a potential chiral building block for polycyclic terpenoids containing a five–membered ring having isopropyl and angular methyl substituents, such as erinacin A and dolatriol, was achieved over 11 steps from ethyl 2-oxocyclopentane-1-carboxylate. The key synthetic precursor for this triflate was ethyl (1S,2R)-2-hydroxycyclopentanecarboxylate (>99% ee), which was prepared by a lipase-catalyzed enantioselective hydrolysis of the corresponding racemic acetate. The antipodal (S)-triflate is expected to be the synthetic intermediate for another group of terpenoids involving hamigeran B and stolonidiol. Enantiomerically pure (1R,2S)-hydroxyester (>99% ee) was prepared in high yield using the asymmetric reduction of the oxoester with commercially available carbonyl reductase, “Chiralscreen OH”-E001.
The fluoroalkene motif as a surrogate of the amide bond: Syntheses of AA-Ψ[(Z) and (E)-CFCH]-Pro pseudodipeptides and an Enalapril analogue
Villiers, Emilie,Couve-Bonnaire, Samuel,Cahard, Dominique,Pannecoucke, Xavier
, p. 7054 - 7062 (2015/08/19)
This work describes the optimization process for the synthesis of pseudodipeptides featuring a proline bound to another amino acid through a fluoroalkene moiety that act as an amide bond surrogate. The synthetic methodology is extended to non-peptidic molecules as demonstrated in the design and synthesis of an Enalapril analogue.
Candida antarctica lipase B-catalyzed reactions of β-hydroxy esters: Competition of acylation and hydrolysis
Forro, Eniko,Galla, Zsolt,Fueloep, Ferenc
, p. 92 - 97 (2013/11/19)
The ester function of ethyl cis-(±)-2-hydroxycyclopentane-1- carboxylate [(±)-1] and ethyl (±)-5-hydroxycyclopent-1- enecarboxylate [(±)-2] was demonstrated to undergo hydrolysis, as a side-reaction, during asymmetric (E > 200) O-acylation with Candida antarctica lipase B (CAL-B) as catalyst and vinyl acetate as acyl donor in t-BuOMe at 30 C. This competition of acylation and undesirable hydrolysis draws attention to CAL-B-catalyzed non-hydrolytic resolutions where the substrates contain any hydrolysable functions. Enantiomerically enriched cis-2-hydroxycyclopentane-1-carboxylic acid (ee = 90%) and 5-hydroxycyclopent-1- enecarboxylic acid (ee = 47%) were prepared through de novo CAL-B-catalyzed hydrolysis of (±)-1 and (±)-2 with added H2O in t-BuOMe at 30 C.
Straightforward asymmetric synthesis of Ala-Ψ[CF=CH]-pro, a proline-containing pseudodipeptide bearing a fluoroolefin as a peptide bond mimic
Dutheuil, Guillaume,Pierry, Camille,Villiers, Emilie,Couve-Bonnaire, Samuel,Pannecoucke, Xavier
, p. 1320 - 1325 (2013/05/22)
From ethyl-2-oxocyclopentanecarboxylate, we developed an asymmetric synthesis of the fluorinated dipeptide Ala-Ψ[(Z)CFCH]-Pro analogue of the transoid parent dipeptide. The fluorinated pseudodipeptide could be incorporated into various peptides or proteins for conformational, structural studies and biological activity studies and could also play a relevant role as an enzyme inhibitor.
Synthesis of isopeptide epoxide peptidomimetics
Majumdar, Debatosh,Alexander, Matthew D.,Coward, James K.
scheme or table, p. 617 - 627 (2009/06/28)
Two epoxide-containing peptidomimetics of the isopeptide, glutamyl-γ-glutamate, have been synthesized via a route that should be generally applicable to the synthesis of isopeptide analogues in which an oxirane replaces the scissile peptide bond. Enzymes
