40456-50-6Relevant articles and documents
Asymmetric Chemoenzymatic Synthesis of (?)-Podophyllotoxin and Related Aryltetralin Lignans
Li, Jian,Zhang, Xiao,Renata, Hans
supporting information, p. 11657 - 11660 (2019/08/02)
(?)-Podophyllotoxin is one of the most potent microtubule depolymerizing agents and has served as an important lead compound in antineoplastic drug discovery. Reported here is a short chemoenzymatic total synthesis of (?)-podophyllotoxin and related aryltetralin lignans. Vital to this approach is the use of an enzymatic oxidative C?C coupling reaction to construct the tetracyclic core of the natural product in a diastereoselective fashion. This strategy allows gram-scale access to (?)-deoxypodophyllotoxin and is readily adaptable to the preparation of related aryltetralin lignans.
TRIP-Catalyzed Asymmetric Synthesis of (+)-Yatein, (-)-α-Conidendrin, (+)-Isostegane, and (+)-Neoisostegane
Hartmann, Peter,Lazzarotto, Mattia,Steiner, Lorenz,Cigan, Emmanuel,Poschenrieder, Silvan,Sagmeister, Peter,Fuchs, Michael
, p. 5831 - 5837 (2019/04/25)
The asymmetric allylation under the assistance of catalytic amounts of 3,3′-bis(2,4,6-triisopropylphenyl)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate (TRIP) allows the concise construction of the lignan scaffold from simple aldehydes and allylic bromides with full control of the two formed stereocenters. This young methodology has been employed to synthesize four naturally and pharmaceutically active lignans. Members of the dibenzylbutyrolactone, the tetraline, and the dibenzocyclooctadiene classes have been synthesized in 40-47% overall yield along four-step synthetic routes.
Catalytic Hydrogenolysis of Enantioenriched Donor–Acceptor Cyclopropanes Using H2 and Palladium on Charcoal
Sone, Yoshitomo,Kimura, Yumi,Ota, Ryotaro,Mochizuki, Takehito,Ito, Junki,Nishii, Yoshinori
, p. 2842 - 2847 (2017/05/29)
The hydrogenolysis of enantioenriched donor–acceptor (D–A) cyclopropanes using H2 (1 atm) and a catalytic amount of palladium on charcoal gave trans-α-alkoxycarbonyl-β-benzyl-γ-lactones or β-substituted γ-aryl-α,α-diesters with high enantiomeric excess. The reaction was also used as a key step in the asymmetric total synthesis of yatein with high ee and excellent dr. This demonstrates the utility of this new protocol for the asymmetric synthesis of trans-α,β-disubstituted γ-butyrolactones. D–A cyclopropanes containing electron-withdrawing groups at the β-position were not susceptible to hydrogenolysis under these conditions. The reductive ring-opening of a D–A cyclopropane using D2 instead of H2 generated the corresponding monodeuterated product.
