65857-83-2Relevant academic research and scientific papers
Synthesis of Bikaverin
Katagiri, Nobuya,Nakano, Jun,Kato, Tetsuzo
, p. 2710 - 2716 (2007/10/02)
The total synthesis of bikaverin (1b) is described, from everninic acid (5) and 3,5-dihydrobenzoic acid (6).Dieckmann condensation of methyl 2-acetyl-3,5-bis(benzyloxy)phenylacetate (14), synthesised from (6), followed by treatment with protected everninic acid chloride (9) gave 1,3-bisbenzyloxy-6,8-bis(2-benzyloxy-4-methoxy-6-methylbenzyloxy)naphthalene (16).Photoinduced Fries rearrangement of (16) afforded 1,3-bis(benzyloxy)-7-(2-benzyloxy-4-methoxy-6-methylbenzoyl)-6-(2-benzyloxy-4-methoxy-6-methylbenzoyloxy)-8-hydroxynaphthalene (23).Ring closure of (23) with tetramethylammonium hydroxide in pyridine gave the angular benzoxanthene, 1,3-bis(benzyloxy-6-hydroxy)-10-methoxy-8-methylbenzoxanthen-7-one (25), which was oxidized with potassium dichromate to give the orthoquinone, 1,3-bis(benzyloxy)-10-methoxy-8-methylbenzoxanthen-5,6,7-trione (28).By a novel type of rearrangement, (28) was transformed into the linear benzoxanthen, 8,10-bis(benzyloxy)-3-methoxy-1-methylbenzoxanthen-6,11,12-trione (29) by treatment with silica gel.Oxidation and debenzylation of (29) with manganese dioxide in concentrated H2SO4 gave norbikaverin (1a).
