Tetrahydronaphthalene lignans

Another anti-cancer agent in clinical use is podophyllotoxin (3-59) this has an aryl tetrahydronaphthalene lignan lactone skeleton, and demonstrates potent tubulin-binding, anti-mitotic properties (Scheme 3.16) [30]. The Sherburn group [31] prepared this molecule by a tris(trimethylsilyl)silane promoted conversion of thionocarbonate 3-55 into the lactone 3-58, which proceeded with a yield of 38 %. As intermediates, the radicals 3-56 and 3-57 can be assumed. 

Rahman, M. A., Katayama, T., Suzuki, T., Yoshihara, Y. and Nakagawa, T. (2007) Stereochemistry and biosynthesis of (-1-)—lyoniresinol, a syringyl tetrahydronaphthalene lignan in Lyonia ovalifolia var. elliptica It feeding experiments with C labeled precursors. /. INood Set, 53,114—20. 

Another cyclisation providing a new bond C-7/C-6" yields cyclolignans (cyclic lignans), which can be considered derivatives of naphthalene or tetrahydronaphthalene (10-104). 

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