18238-28-3Relevant academic research and scientific papers
Platinum-catalyzed α,β-unsaturated carbene formation in the formal syntheses of frondosin B and liphagal
Huynh, Khoi Q.,Seizert, Curtis A.,Ozumerzifon, Tarik J.,Allegretti, Paul A.,Ferreira, Eric M.
, p. 294 - 297 (2017)
Formal syntheses of tetracyclic terpenoids frondosin B and liphagal are described. Both synthetic routes rely on the use of platinum-catalyzed α,β-unsaturated carbene formation for the key C-C bond forming transformations. The successful route toward frondosin B utilizes a formal (4 + 3) cycloaddition, while the liphagal synthesis features the vinylogous addition of an enol nucleophile as a key step. Both synthetic routes are discussed, revealing insights into structural requirements in the catalytic a,β-unsaturated carbene reaction manifold.
Synthesis of (±)-nosyberkol (isotuberculosinol, revised structure of edaxadiene) and (±)-tuberculosinol
Maugel, Nathan,Mann, Francis M.,Hillwig, Matthew L.,Peters, Reuben J.,Snider, Barry B.
, p. 2626 - 2629 (2010)
Me2AlCl-catalyzed Diels-Alder reaction of N-tigloyloxazolidinone with 6,6-dimethyl-1-vinylcyclohexene selectively provided the exo adduct, which was converted to nosyberkol (isotuberculosinol) and tuberculosinol. The spectral data for nosyberko
Stereoselective Synthesis of 1-Tuberculosinyl Adenosine; A Virulence Factor of Mycobacterium tuberculosis
Buter, Jeffrey,Heijnen, Dorus,Wan, Ieng Chim,Bickelhaupt, F. Matthias,Young, David C.,Otten, Edwin,Moody, D. Branch,Minnaard, Adriaan J.
supporting information, p. 6686 - 6696 (2016/08/16)
Despite its status as one of the world's most prevalent and deadly bacterial pathogens, Mycobacterium tuberculosis (Mtb) infection is not routinely diagnosed by rapid and highly reliable tests. A program to discover Mtb-specific biomarkers recently identified two natural compounds, 1-tuberculosinyl adenosine (1-TbAd) and N6-tuberculosinyl adenosine (N6-TbAd). Based on their association with virulence, the lack of similar compounds in nature, the presence of multiple stereocenters, and the need for abundant products to develop diagnostic tests, synthesis of these compounds was considered to be of high value but challenging. Here, a multigram-scale stereoselective synthesis of 1-TbAd and N6-TbAd is described. As a key-step, a chiral auxiliary-mediated Diels-Alder cycloaddition was developed, introducing the three stereocenters with a high exo endo ratio (10:1) and excellent enantioselectivity (>98% ee). This constitutes the first entry into the stereoselective synthesis of diterpenes with the halimane skeleton. Computational studies explain the observed stereochemical outcome.
Total synthesis of (+/-)-frondosin B and (+/-)-5-epi-liphagal by using a concise (4+3) cycloaddition approach
Laplace, Duchan R.,Verbraeken, Bart,Van Hecke, Kristof,Winne, Johan M.
, p. 253 - 262 (2014/01/17)
A recently developed (4+3) cycloaddition between dienes and furfuryl alcohols, as precursors of oxyallyl-type cations, has been used as a key step in the racemic syntheses of two natural products: frondosin B and liphagal. This work demonstrates the synthetic potential of this cycloaddition reaction, and offers a short synthetic route to an interesting family of natural products. A full account of these synthetic studies is presented, further illustrating the mechanism, scope, and limitations of this straightforward synthetic method for seven-membered rings. Cycloheptanes: Furfuryl alcohols serve as effective three-carbon dienophiles for a wide range of dienes in stereoselective cycloaddition reactions. This efficient reaction has been used to prepare two cycloheptanoid natural products, offering a conceptually straightforward and short synthetic entry into a biologically interesting class of polycyclic meroterpenoids (see scheme; TFA = trifluoroacetic acid). Copyright
A novel, facile approach to frondosin B and 5-epi-liphagal via a new [4 + 3]-cycloaddition
Zhang, Jie,Li, Liqi,Wang, Yongxiang,Wang, Wenjing,Xue, Jijun,Li, Ying
supporting information, p. 4528 - 4530 (2012/11/07)
A new [4 + 3]-cycloaddition between benzofuran allylic alcohols and dienes, promoted by camphorsulfonic acid, has been identified. A novel strategy which used this cycloaddition as a key step has been developed for the synthesis of 6,7,5-tricyclic skeleta
A Study of the Diels-Alder Regioselectivity of Substituted Vinyl Cyclohexenes
Tanis, Steven P.,Abdallah, Yousef M.
, p. 251 - 260 (2007/10/02)
The regioselectivity of dienes 6a and 6b in Diels-Alder reactions with ethylenic and acetylenic dienophilic was examined and found to be good-excellent.An improved synthesis of diene 6a via a CuSO4 mediated dehydration of the vinyl carbinol precursor is described.
