17301-91-6Relevant articles and documents
Chemoenzymatic Total Synthesis of Deoxy-, epi-, and Podophyllotoxin and a Biocatalytic Kinetic Resolution of Dibenzylbutyrolactones
Lazzarotto, Mattia,Hammerer, Lucas,Hetmann, Michael,Borg, Annika,Schmermund, Luca,Steiner, Lorenz,Hartmann, Peter,Belaj, Ferdinand,Kroutil, Wolfgang,Gruber, Karl,Fuchs, Michael
, p. 8226 - 8230 (2019/05/21)
Podophyllotoxin is probably the most prominent representative of lignan natural products. Deoxy-, epi-, and podophyllotoxin, which are all precursors to frequently used chemotherapeutic agents, were prepared by a stereodivergent biotransformation and a biocatalytic kinetic resolution of the corresponding dibenzylbutyrolactones with the same 2-oxoglutarate-dependent dioxygenase. The reaction can be conducted on 2 g scale, and the enzyme allows tailoring of the initial, “natural” structure and thus transforms various non-natural derivatives. Depending on the substitution pattern, the enzyme performs an oxidative C?C bond formation by C?H activation or hydroxylation at the benzylic position prone to ring closure.
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.
