35436-57-8Relevant articles and documents
Studies towards the synthesis of FCRR toxin: An expeditious entry into 7-5-6 ring systems via [5+2] oxidopyrylium-alkene cycloaddition
Murali Krishna,Trivedi
, p. 257 - 259 (2004)
Synthetic studies towards the diterpene natural product FCRR toxin have been undertaken. An intermolecular [5+2] oxidopyrylium-alkene cycloaddition reaction was employed to construct the 7-5-6 tricyclic framework. The reaction proceeded with very high regio- and stereoselectivity and the bridging ether was reductively cleaved to unmask the carbocycle.
A solvent-free catalytic protocol for the Achmatowicz rearrangement
Zhao, Guodong,Tong, Rongbiao
, p. 64 - 68 (2019)
Reported here is the development of an environmentally friendly catalytic (KBr/oxone) and solvent-free protocol for the Achmatowicz rearrangement (AchR). Different from all previous methods is that the use of chromatographic alumina (Al2O3) allows AchR to proceed smoothly in the absence of any organic solvent and therefore considerably facilitates the subsequent workup and purification with minimal environmental impacts. Importantly, this protocol allows for scaling up (from milligram to gram), recycling of the Al2O3, and integrating with other reactions in a one-pot sequential manner.
Mechanistic insights into the vanadium-catalyzed achmatowicz rearrangement of furfurol
Ji, Yining,Benkovics, Tamas,Beutner, Gregory L.,Sfouggatakis, Chris,Eastgate, Martin D.,Blackmond, Donna G.
, p. 1696 - 1702 (2015)
The Achmatowicz rearrangement is a powerful method for the construction of pyranones from simple furan derivatives. Here, we describe the development of improved reaction conditions and an interrogation into the fate of the metal center during this interesting transformation. The reaction to form the synthetically important lactol, 6-hydroxy-2H-pyran-3(6H)-one (3), proceeds cleanly in the presence of tert-butyl hydroperoxide (TBHP, 2) using low loadings of VO(OiPr)3 as catalyst. The nonaqueous conditions developed herein allow for easy isolation of product 3 and synthetically important derivatives, a key advantage of this new protocol. Detailed experimental, spectroscopic, and kinetic studies along with kinetic modeling of the catalytic cycle support a positive-order dependence in both furfurol and TBHP concentrations, first-order dependence in catalyst (VO(OiPr)3), and a negative dependence on the 2-methyl-2-propanol (4) concentration. 51V-NMR spectroscopic studies revealed that 2-methyl-2-propanol (4) competes with substrates for binding to the metal center, rationalizing its inhibitory effect.
[6+3] Cycloaddition of pentafulvenes with 3-oxidopyrylium betaine: a novel methodology toward the synthesis of 5-8 fused oxabridged cyclooctanoids
Krishnan, K. Syam,Sajisha,Anas,Suresh,Bhadbhade, Mohan M.,Bhosekar, Gaurav V.,Radhakrishnan
, p. 5952 - 5961 (2006)
Pentafulvenes undergo a facile [6+3] cycloaddition with 3-oxidopyrylium betaine, generated from the corresponding pyranulose acetate, leading to the formation of 5-8 fused oxabridged cyclooctanoids. The product is formed by a [6+3] cycloaddition, followed
Palladium-Catalyzed Regioselective and Diastereoselective C-Glycosylation by Allyl-Allyl Coupling
Li, Junhao,Zheng, Nan,Duan, Xuelun,Li, Rui,Song, Wangze
supporting information, p. 846 - 850 (2020/12/13)
A Pd-catalyzed C-glycosylation reaction was developed by allyl-allyl coupling process using Achmatowicz rearrangement products as donors and methylcoumarins as acceptors under mild conditions. This method featured regio- and diastereoselectivities, stereo
Enantioselective 1,3-Dipolar [6+4] Cycloaddition of Pyrylium Ions and Fulvenes towards Cyclooctanoids
McLeod, David,Cherubini-Celli, Alessio,Sivasothirajah, Nisanhi,McCulley, Christina H.,Christensen, Mette Louise,J?rgensen, Karl Anker
supporting information, p. 11417 - 11422 (2020/08/06)
Organocatalytic enantioselective 1,3-dipolar [6+4] cycloadditions of pyrylium ion intermediates with fulvenes promoted by a chiral primary amine catalyst have been developed to proceed in moderate to good yields and high enantioselectivities. The resultant chiral bicyclo[6.3.0]undecane scaffold containing a transannular bridging ether is densely functionalised providing a rigid scaffold for further manipulations. Computational studies give important insights into the role of the primary amine catalyst. Analysis of the reaction shows that the catalytic reaction proceeds in a step-wise manner and rationalises the stereochemical outcome of the reaction. Several stereoselective complexity-generating transformations, facilitated by the diverse functional groups and transannular bridge, are presented, highlighting the versatility of the core towards a number of the cyclooctanoid natural products.
Biorefinery via Achmatowicz Rearrangement: Synthesis of Pentane-1,2,5-triol from Furfuryl Alcohol
Simeonov, Svilen P.,Ravutsov, Martin A.,Mihovilovic, Marko D.
, p. 2748 - 2754 (2019/06/24)
A new scalable synthesis of pentane-1,2,5-triol from the furanics platform has been developed. Excellent yields of up to 92 % are obtained under flow conditions by using readily available catalysts from the existing pool. The strategy exploits the highly functionalized Achmatowicz product as a key intermediate, thus circumventing problems related to the low reactivity of the parent furfural and furfuryl alcohol. Besides expanding the portfolio of biomass-derived C5 alcohols, this strategy may also be further applied for the establishment of a versatile bio-based chemical platform.
