Photochemical reactions. Part I. A new route to tetradehydropodophyllotoxin, taiwanin E, and related compounds
Abstract
Irradiation of ortho-substituted aromatic aldehydes generates reactive intermediates which can be trapped with dienophiles. Dehydration of the trapped products allows formation of substituted naphthalenes, whereas mild oxidation affords the corresponding naphthols. In this way the lignans tetradehydropodophyllotoxin. taiwanins E and C, and justicidin E have been prepared.