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Carpenter, Brian George (1965) Chemistry of lignans. Doctoral thesis, Sir John Cass College.
Preliminary experiments with a view to determine the mode of biosynthesis of lignans, in vivo, have been carried out by feeding a number of carbon-14 labelled compounds to botanical specimens of Podophyllum Emodi and Cicuta Virosa. A variety of techniques of feeding, at different stages of the growing season were tried, translocation of the active material demonstrated, and a small amount of radioactivity found in the initially isolated podophyllum resin; specific activity of the lignan was not however found.
Both anticoincidence and liquid scintillation counters have been calibrated to count active resin or lignan, including corrections for self-quenching.
The methods of preparing 1-phenylnaphthalenes have been discussed with special attention given to reactions which do not disrupt methylenedioxy ethers.
With podophyllotoxin as the focus of interest the Stobbe condensation route to related diarylidenesuccinic anhydrides has been expanded, including the development of the reagent lithium tri-t-butoxyaluminium hydride for the synthesis of trimethylgallaldehyde. αβ-Di-3,4,5-trimethoxybenzylidenesuccinic anhydride and α-3,4-methylenedioxy-β-3,4,5-tri- methoxybenzylidenesuccinic anhydride have both been cyclised to 1-phenyl- naphthalene-2,3-dicarboxylic anhydrides by irradiation with ultra-violet light, and a number of alternative procedures investigated. The unsymmetrical diarylidene compound gave rise to two isomeric 1-pheaylnaphthalene-2,3-dicarboxylic anhydrides, and the structural configurations of these have been determined by ultra-violet absorption spectroscopy and nuclear magnetic resonance spectroscopy.
Attempts to reduce the carboxylic anhydride function to a lactone with lithium aluminium hydride appears to have been successful in the case of 6,7,8-trimethoxy-1-(3',4',5'-trimethoxyphenyl)-naphthalene-2,3-dicarboxylic anhydride but not with 6,7-methylenedioxy-1-(3,4,5-trimethoxyphenyl)-naphthalene-2,3-dicarboxylic anhydride.
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