01496nas a2200169   4500008004100000022001400041245017400055210006900229260007100298300001400369490000700383520074000390100002101130700002601151700001901177856013001196       2006                        eng d  a0022-326300aFacile synthesis of 1,3,7-trihydroxyxanthone and its regioselective coupling reactions with prenal: simple and efficient access to osajaxanthone and nigrolineaxanthone F0 aFacile synthesis of 137trihydroxyxanthone and its regioselective  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN  a4992-49950 v713 a<p>A facile five-step synthesis of naturally occurring 1,3,7-trihydroxyxanthone has been described starting from 1,3,5-trimethoxybenzene via NBS-induced nuclear bromination, lithiation followed by an in situ benzoylation with methyl 2,5-dibenzyloxybenzoate, selective deprotection of the two benzyl groups, base-catalyzed intramolecular cyclization, and demethylations pathway with 62% overall yield. The regioselective coupling reactions of 1,3,7-trihydroxyxanthone with prenal in the presence of calcium hydroxide at room temperature and under thermal conditions at 140-150 degrees C have been demonstrated to exclusively obtain the natural products osajaxanthone in 75% yield and nigrolineaxanthone F in 98% yield, respectively.</p>1 aMondal, Mukulesh1 aPuranik, Vedavati, G.1 aArgade, N., P.  uhttps://library.ncl.res.in/content/facile-synthesis-137-trihydroxyxanthone-and-its-regioselective-coupling-reactions-prenal-0