77071-95-5Relevant academic research and scientific papers
Formal synthesis of (-)-podophyllotoxin through the photocyclization of an axially chiral 3,4-bisbenzylidene succinate amide ester-a flow photochemistry approach
Lisiecki, Kamil,Krawczyk, Krzysztof K.,Roszkowski, Piotr,Maurin, Jan K.,Czarnocki, Zbigniew
, p. 460 - 469 (2015)
We have developed a strategy for the stereoselective synthesis of cyclolignans related to podophyllotoxin and its derivatives. The crucial step of the synthesis is the photocyclization of a chiral atropoisomeric 1,2-bisbenzylidenesuccinate amide ester, which can be prepared from suitable aromatic aldehydes, diethyl succinate and l-prolinol. The photocyclization was found to be more efficient when irradiation was performed in a home-built continuous flow photochemical reactor. The in-flow irradiation also allowed us to perform the reaction on a multigram scale. The chiral auxiliary was removed by reductive cleavage with the Schwartz's reagent to give the cytotoxic 1R,2R-cis-podophyllic aldehyde, which in turn could be easily reduced to the corresponding alcohol, completing the formal synthesis of (-)-podophyllotoxin.
Unusual visible-light photolytic cleavage of tertiary amides during the synthesis of cyclolignans related to podophyllotoxin
Lisiecki, Kamil,Krawczyk, Krzysztof K.,Roszkowski, Piotr,Maurin, Jan K.,Budzianowski, Armand,Czarnocki, Zbigniew
, p. 6316 - 6328 (2017/10/06)
During the attempted photochemical cyclization of 2,3-bisbenzylidene-γ-hydroxybutyric acid cyclic amide ester, it was observed that a γ-butyrolactone ring was formed, which was concurrent with the release of the amine fragment from the amide. The process occurs with high yield giving rise to the formation of β-apopicropodophyllin and its regioisomer. Additional experiments confirmed the photochemical nature of this transformation, and that it is independent from the photocyclization of the benzylidene groups – a typical reactivity for the members of the fulgide family. In contrast to the latter UV-driven cyclization, the photochemical cleavage of the amide was proven to proceed under irradiation with visible light.
Synthesis, anti-virus and anti-tumour activities of dibenzylbutyrolactone lignans and their analogues
Xia, Yamu,You, Jia,Zhang, Yuanyuan,Su, Zhongliang
experimental part, p. 565 - 569 (2010/03/03)
An efficient synthesis of dibenzylbutyrolactone lignans and their analogues has been developed. Based on a Stobbe condensation of piperonal or veratraldehyde with diethylsuccinate and alkylation with 3,4- methylenedioxybenzyl bromide to give the skeleton
