jo061810h_si_001.pdf (5.88 MB)
Total Synthesis of Natural and Unnatural Lamellarins with Saturated and Unsaturated D-Rings
journal contribution
posted on 2006-12-08, 00:00 authored by Poonsakdi Ploypradith, Thaninee Petchmanee, Poolsak Sahakitpichan, Nichole D. Litvinas, Somsak RuchirawatTwenty-eight natural and unnatural lamellarins with either a saturated or an unsaturated D-ring were
synthesized according to our developed synthetic route. The key step involved the Michael addition/ring
closure (Mi−RC) of the benzyldihydroisoquinoline and α-nitrocinnamate derivatives, which provided
the 2-carboethoxypyrrole intermediates in moderate to good yields (up to 78% yield). Subsequent
hydrogenolysis/lactonization furnished lamellarins with a saturated D-ring in excellent yields (up to 93%
yield). DDQ oxidation of the saturated lamellarin acetates led directly to the corresponding unsaturated
analogues in 54−95% yield. In addition, only two steps in our developed strategy require column
chromatography.