An intramolecular diels-alder reaction. A simple synthesis of γ-apopicropodophyllin.

✍ Scribed by L.H. Klemm; K.W. Gopinath

• Publisher: Elsevier Science
• Year: 1963
• Tongue: French
• Weight: 135 KB
• Volume: 4
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)90810-x

✦ Synopsis

Y-AP~PICROP~D~PI~YLLIN (II) was isolated as a secondary degradation product resulting from dehydration of the naturally occurring, tumor-necrotizing compound podophyllotoxln. 1 II was found to be identical with a compound previously synthesized by Haworth and Richardson2 by a multiple-step procedure, which was Investigated further by Schrecker and Hartwell. Interest in general syntheses of II and its analogous lignans of the 4-aryltetrahydronaphthalene type4 has led us to investigate the possibility of effecting a simple intramolecular Diels-Alder condensation between two open-chain unsaturated Ar-C-C-C units (lignan building blocks), joined together at the Y-carbons In order to facilitate close proximity of these units. Needed to form II by such a scheme is