73119-39-8

Upstream product

• 86-81-7 3,4,5-trimethoxy-benzaldehyde 
• 123-25-1 succinic acid diethyl ester 
• 106-65-0 Dimethyl succinate 

Downstream Products

• 721396-14-1 (1S,2R)-1-(3,4,5-trimethoxyphenyl)-6,7,8-trimethoxy-1,2-dihydronaphthalene-2,3-dicarboxylate (-)-ephedrine cyclic amide ester 
• 117407-00-8 2,3-bis(3,4,5-trimethoxybenzyl)-4-butanolide 

Relevant academic research and scientific papers

Unusual visible-light photolytic cleavage of tertiary amides during the synthesis of cyclolignans related to podophyllotoxin

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.

New synthetic route to butanolide lignans by a ruthenium complex catalyzed hydrogenation of the corresponding Stobbe's fulgenic acids

A new two-step total synthesis of butanolide lignans (or dibenzylbutyrolactone lignans) is described, which affords the title compounds in good yield and with a very short work-up time. It involves a ruthenium carbonyl hydride complex-catalyzed hydrogenation of the corresponding dibenzylidene succinic acids (fulgenic acids). Since the catalytic hydrogenation (second step) is a total yielding process, the overall yield determining step is the preparation of the fulgenic acid intermediates by the Stobbe condensation (first step), which has consequently been revised to improve many details. This simple process moreover allows hexadeuterated butanolide lignans to be readily obtained for isotopic dilution mass spectral measurements. The syntheses of a selection of lignans, namely enterolactone, matairesinol, hinokinin, dimethylmatairesinol and cordigerine, are described to illustrate the whole procedure.