90545-43-0Relevant academic research and scientific papers
Four-Step One-Pot Catalytic Asymmetric Synthesis of Polysubstituted Tricyclic Compounds: Lipase-Catalyzed Dynamic Kinetic Resolution Followed by an Intramolecular Diels-Alder Reaction
Tsuchimochi, Izuru,Hori, Shuhei,Takeuchi, Yasuo,Egi, Masahiro,Satoh, Tomo-O,Kanomata, Kyohei,Ikawa, Takashi,Akai, Shuji
, p. 822 - 828 (2021/02/16)
Starting from readily available tertiary alcohols, four different reactions (a 1,3-migration of a hydroxy group, kinetic resolution, racemization, and an intramolecular Diels-Alder reaction) took place under co-catalysis by lipase and oxovanadium compounds in a one-pot process to produce polysubstituted tricyclic carbon frameworks in high yields and with high enantioselectivities. The key to the success of this process was the discovery that a silyl group attached to the terminal carbon of the vinyl moiety completely controls the direction of hydroxy group migration.
1,n-rearrangement of allylic alcohols promoted by hot water: Application to the synthesis of navenone B, a polyene natural product
Li, Pei-Fang,Wang, Heng-Lu,Qu, Jin
, p. 3955 - 3962 (2014/05/20)
It was reported for the first time that hot water as a mildly acidic catalyst efficiently promoted 1,n-rearrangement (n = 3, 5, 7, 9) of allylic alcohols. In some cases, the rearrangement reactions joined isolated C-C double or triple bonds to generate conjugated polyene or enyne structure motifs. We used the 1,3-rearrangement reaction of an allylic alcohol in hot water as part of an attractive new strategy for construction of the polyene natural product navenone B by iterative use of a Grignard reaction, a 1,3-rearrangement of the resulting allylic alcohol, and subsequent oxidation of the rearranged product.
A ring-closing enyne metathesis approach to functionalized semicyclic dienes: The total synthesis of (-)-tetrangomycin
Moodie, Lindon W. K.,Larsen, David S.
supporting information, p. 1684 - 1694 (2014/03/21)
The angucycline antibiotic (-)-tetrangomycin was synthesized in 13 steps (11 % overall yield) by using a stereoselective Diels-Alder reaction between a naphthoquinone and a semicyclic diene to construct the benz[a]anthraquinone ring system. The diene inte
A Ring-Closing Enyne Metathesis Approach to Functionalized Semicyclic Dienes: The Total Synthesis of (-)-Tetrangomycin
Moodie, Lindon W. K.,Larsen, David S.
supporting information, p. 1684 - 1694 (2015/10/05)
The angucycline antibiotic (-)-tetrangomycin was synthesized in 13 steps (11 % overall yield) by using a stereoselective Diels-Alder reaction between a naphthoquinone and a semicyclic diene to construct the benz[a]anthraquinone ring system. The diene inte
From planning to optimization: Total synthesis of valerenic acid and some bioactive derivatives
Ramharter, Juergen,Mulzer, Johann
experimental part, p. 2041 - 2053 (2012/05/05)
A detailed study of the total synthesis of valerenic acid, a well known GABAA receptor subtype modulator, is described. Both successful as well as unsuccessful attempts towards the synthesis of the title compound are presented, including four different strategies to synthesize one of the key intermediates. The first two strategies are based on epoxides provided from the chiral pool, whereas the last two approaches rest on stereocontrolled modifications of 2-cyclopentenone. The streamlined synthesis implements a new one-pot reaction, which combines the addition of a Grignard species with an acid-catalyzed isomerization of the intermediate allylic alcohol. Further highlights are a stereo- and regioselective hydroxy-directed Diels-Alder reaction, a hydroxy-directed hydrogenation, and a final Negishi coupling reaction. After optimization of our synthesis, the preparation of several easily available derivatives is also discussed. Amides obtained by functionalization of the carboxyl group are more than twice as active as valerenic acid. The development and optimization of four different approaches towards valerenic acid (1) are described. The shortest approach spans 10 steps and provides valerenic acid in 25 % overall yield by incorporating a new one-pot reaction, an extremely stereo- and regioselective metal-coordinated Diels-Alder reaction, a hydroxy-directed hydrogenation, and a final Negishi coupling reaction. Copyright
Mild and tunable benzoic acid catalysts for rearrangement reactions of allylic alcohols
McCubbin, J. Adam,Voth, Samantha,Krokhin, Oleg V.
experimental part, p. 8537 - 8542 (2011/12/14)
An efficient and simple catalytic method for the isomerization of readily prepared allylic alcohols is described. We focus particularly on cyclic examples and the synthesis of unusual enyne and dienols. The benzoic acid catalysts employed are commercially available and very inexpensive and can be tuned for reactivity and substrate sensitivity.
Efficient and scalable one-Pot Synthesis of 2,4-Dienols from cycloalkenones: Optimized total synthesis of valerenic acid
Ramharter, Juergen,Mulzer, Johann
supporting information; experimental part, p. 5310 - 5313 (2011/12/04)
A mild and selective one-pot procedure to provide 2,4-dienols from simple cycloalkenones in high yields is described. This transformation is based on the in situ formation of acid-labile allylic alcohols, which on treatment with trifluoroacetic acid under
Acceleration effect of allylic hydroxy group on ring-closing enyne metathesis of terminal alkynes: scope and application to the synthesis of isofagomine
Imahori, Tatsushi,Ojima, Hidetomo,Tateyama, Hiroki,Mihara, Yukiko,Takahata, Hiroki
, p. 265 - 268 (2008/03/30)
An interesting allylic substituent effect on ring-closing enyne metathesis has been found. An allylic hydroxy group on enyne substrates accelerates ring-closing enyne metathesis of terminal alkynes. The reaction proceeds smoothly without ethylene atmosphere and/or more reactive newer generation Ru-carbene catalysts, which are generally necessary to promote the reaction. This efficient reaction was applied to the synthesis of isofagomine.
Acceleration effect of an allylic hydroxy group on ring-closing enyne metathesis of terminal alkynes: Scope, application, and mechanistic insights
Imahori, Tatsushi,Ojima, Hidetomo,Yoshimura, Yuichi,Takahata, Hiroki
experimental part, p. 10762 - 10771 (2009/12/01)
An interesting acceleration effect of an allylic hydroxy group on ring-closing enyne metathesis has been found. Ring-closing enyne metathesis of terminal alkynes possessing an allylic hydroxy group proceeded smoothly without the ethylene atmosphere generally necessary to promote the reaction. The synthesis of (+)-isofagomine with the aid of this efficient reaction has been demonstrated. Mechanistic studies of the acceleration effect were also carried out. Results of NMR studies suggested that the reaction proceeded via an "ene-then-yne" pathway. Kinetic studies indicated switching of the rate-determining step as a consequence of the presence of an allylic hydroxy group. These results suggest acceleration of the reentry step of Ru-carbene species by the allylic hydroxy group.
A microwave-accelerated intramolecular diels-alder reaction approach to compactin
Takatori, Kazuhiko,Hasegawa, Kazushi,Narai, Satoshi,Kajiwara, Masahiro
, p. 525 - 528 (2007/10/03)
Microwave irradiation drastically accelerated the intramolecular Diels-Alder reactions of 5a-c as compared with conventional heating. The resulting carboxylic acid (7c) was converted to the decalin unit (2 a), which is a possible key intermediate for synt
