334976-31-7Relevant academic research and scientific papers
Fischer Carbene Pentannulation with Alkynes Having Adjacent Carbonate or Acyloxy Groups: Synthesis of 3-Substituted 1-Indanones
Bhattacharyya, Shubhankar,Chavan, Vijay P.,Fernandes, Rodney A.,Gholap, Sachin P.,Saiyed, Akeel S.
, p. 3438 - 3443 (2020)
Various aryl Fischer carbenes reacted with alkynes having adjacent acyloxy or carbonate groups to regioselectively deliver 3-substituted 1-indanones. The acyloxy or carbonate group probably coordinates with the Cr metal to give a tetra-coordinated chromium complex forming a six-membered ring that retards CO insertion for ketene formation, which is required for benzannulation. Alternatively, the ortho position aryl ring attack results in pentannulation, providing regioselectively 3-substituted 1-indanones. The method is extended to the synthesis of the core structure of 3-epi-mutisianthol.
A Highly Convergent Total Synthesis of Norhalichondrin B
Das, Dipendu,Nicolaou, K. C.,Pan, Saiyong,Rigol, Stephan,Shelke, Yogesh,Ye, Qiuji
, p. 20970 - 20979 (2021/12/14)
A new synthetic strategy for the total synthesis of norhalichondrin B featuring a highly convergent approach and our recently disclosed reverse approach for the synthesis of cyclic ether structural motifs is disclosed. Resulting in the shortest route to norhalichondrin B disclosed thus far, the reported total synthesis was achieved through the synthesis of two almost equally complex fragments whose coupling and short elaboration sequence featured an essential epimerization of the C16 stereocenter occurring concurrently with a simple acid-induced deprotection, a tactic based on a prior study along the synthetic route. This unprecedented strategy within the halichondrin family of natural products could find practical application to the synthesis of other more or less complex natural or designed halichondrin analogues.
Axial-to-Central Chirality Transfer for Construction of Quaternary Stereocenters via Dearomatization of BINOLs
Min, Xiao-Long,Xu, Xu-Ran,He, Ying
supporting information, p. 9188 - 9193 (2019/11/14)
All-carbon quaternary stereocenters are versatile building blocks, and their asymmetric construction has attracted much attention. Herein, we disclose an axial-to-central chirality transfer strategy for the synthesis of chiral quaternary stereocenters via dearomatization of (S)-BINOLs. The reaction proceeded smoothly with a wide range of propargyl carbonates to afford chiral spiro-compounds in high yields with excellent enantioselectivities. In addition, the strategy was extended to kinetic resolution of rac-BINOLs albeit with moderate s value.
Chemoselective o-benzylation of the propargylic hydroxy group in polyols
Lee, Ji Ho,Oh, Chang Ho
, p. 5913 - 5917,5 (2020/09/02)
We have discovered the highly chemoselective benzylation of propargylic hydroxy groups in the presence of other hydroxy groups under very usual conditions involving benzyl bromide and sodium hydroxide in DMF at room temperature. This methodology has a hig
Synthesis of the tetracyclic core of berkelic acid using gold(I)-catalyzed hydroarylation and oxidative radical cyclizations
Brimble, Margaret A.,Haym, Isabell,Sperry, Jonathan,Furkert, Daniel P.
, p. 5820 - 5823 (2013/02/23)
A synthetic approach to the tetracyclic core of berkelic acid is reported using gold(I)-catalyzed intramolecular hydroarylation and oxidative radical cyclizations to effect the key ring-forming steps. The carboxylic acid was introduced via a late-stage palladium-catalyzed carbonylation to afford the core tetracycle with the correct relative stereochemistry for the natural product.
Chiral silver phosphate-catalyzed cycloisomeric kinetic resolution of α-allenic alcohols
Wang, Yan,Zheng, Kuan,Hong, Ran
supporting information; scheme or table, p. 4096 - 4099 (2012/04/10)
A kinetic resolution of α-allenic alcohols is realized through chiral silver phosphate-catalyzed cycloisomerization with high stereoselectivity (selectivity factor up to 189) and tolerance of a variety of functional groups. A mechanistic model is proposed to interpret the origin of the high stereoselectivity and broad substrate scope.
Total synthesis of the phytotoxic stagonolides A and B
Prabhakar, Peddikotla,Rajaram, Singanaboina,Reddy, Dorigondla Kumar,Shekar, Vanam,Venkateswarlu, Yenamandra
experimental part, p. 216 - 221 (2010/05/18)
The chemo-enzymatic and covergent synthesis of stagonolide B and the synthesis of stagonolide A, a phytotoxic 10-membered lactone have been achieved starting from d-ribose with overall yields of 25% and 8.7%, respectively. The synthesis contained simple steps in developing three centers' key intermediates, namely the enzymatic (Novozyme-435) resolution of a propargylic alcohol followed by macrolactonization and RCM.
Synthesis of a 2,3′;6′,3″-terpyridine scaffold as an α-helix mimetic
Davis, Jessica M.,Truong, Anh,Hamilton, Andrew D.
, p. 5405 - 5408 (2007/10/03)
(Chemical Equation Presented) A terpyridine scaffold has been designed as an α-helix mimetic. A facile synthesis of the ortho-functionalized 2,3′-oligopyridine has been accomplished using sequential Bohlmann-Rahtz heteroannulation reactions.
Total synthesis of (-)-stemospironine.
Williams,Fromhold,Earley
, p. 2721 - 2724 (2007/10/03)
[structure: see text]. A stereocontrolled total synthesis of the polycyclic Stemona alkaloid, (-)-stemospironine (1) has been achieved. Key transformations include the use of a Staudinger reaction leading to the aza-Wittig ring closure of the perhydroazepine system. Formation of the vicinal pyrrolidine butyrolactone is described via the stereoselective intramolecular capture of an intermediate aziridinium salt.
