104265-74-9Relevant articles and documents
Total synthesis of two naturally occurring bicyclo[3.2.1]octanoid neolignans.
Wang, Mingyi,Wu, Anxin,Pan, Xinfu,Yang, Hongfang
, p. 5405 - 5407 (2002)
The first total syntheses of the racemates of naturally occurring macrophyllin-type bicyclo[3.2.1]octanoid neolignans, kadsurenin C 3 and kadsurenin L 4, were accomplished starting from vanillin and resorcinol. The acid-catalyzed rearrangement of hydrobenzofuranoid neolignans into bicyclo[3.2.1]octanoid neolignans was used as the key step.
Stereospecific Lewis Acid-Promoted Reactions of Styrenyl Systems with 2-Alkoxy-(6-alkyl)-1,4-benzoquinones: Scope, Limitations, and Synthetic Applications
Engler, Thomas A.,Combrink, Keith D.,Letavic, Michael A.,Lynch, Kenneth O.,Ray, James E.
, p. 6567 - 6587 (2007/10/02)
Titanium(IV)-promoted reactions of various (E)-1-propenylbenzenes with 2-methoxy- and 2-methoxy-6-methyl-1,4-benzoquinones produce trans 2-aryl-6-methoxy-3-(and 4-di)methyl-2,3-dihydro-5-benzofuranols (10-12), rel-(1S,6R,7R,8R)-3-methoxy-8-aryl-7-(and 1-di)methylbicyclooct-3-ene-2,5-diones (2 + 2 cycloadducts, 13-15) and/or rel-(1R,5R,6R,7R)-7-aryl-3-hydroxy-6-(and 4)-methylbicyclooct-3-ene-2,8-diones (5 + 2 cycloadducts, 16/17).In many cases, each of the three products can be obtained selectively in good yield by control of reaction conditions and/or by choice of substituents on the quinone or the propenylbenzene.The dihydrobenzofurans are formed stereoselectively, whereas the formation of the bicyclo systems are stereospecific processes.Thus, reactions of (Z)-1-propenylbenzenes afford rel-(1R,6S,7R,8R)-8-aryl-3-methoxy-7-methylbicyclooct-3-ene-2,5-diones (24, 25).No bicyclosystems are found in reactions of the (Z)-propenylbenzenes.The products all apparently result from a thermally allowed 2? + 4? (2 + 5) cycloaddition of the propenylbenzene with a 2-methoxy-4-oxo-2,5-cyclohexadienyl carbocation intermediate (26) formed by coordination of the Ti(IV) to the C-1 carbonyl oxygen of the quinone.In the cycloaddition, the aryl ring of the propenylbenzene occupies an endo position with respect to the pentadienyl carbocation moiety of 26 and the bicyclo carbocation product of the cycloaddition (28/29) either undergoes dealkylation or rearrangement to yield the observed products.Treatment of the bicylo systems with protic acid effects their rearrangement to the dihydrobenzofuranols.Reactions of 2-propenylbenzenes and arylcycloalkenes with the quinones regioselectively give dihydrobenzofuranols 43-45 and 49-54, respectively; a 2 + 2 cycloadduct is found in low yield in only one case.The 7-aryl-3-hydroxy-6-methylbicyclooct-3-ene-2,8-diones are produced exclusively in reactions of 2-((4-methoxybenzyl)oxy)-1,4-benzoquinones with various propenylbenzenes.Application of these reactions to the synthesis of (+/-)-obtusafuran, (+/-)-liliflol-B, (+/-)-kadsurenone, and (+/-) denudatin are reported.
TOTAL SYNTHESIS OF KADSURENONE AND ITS ANALOGS
Ponpipom, M. M.,Yue, B. Z.,Bugianesi, R. L.,Brooker, D. R.,Chang, M. N.,Shen, T. Y.
, p. 309 - 312 (2007/10/02)
Kadsurenone, a specific receptor antagonist of platelet-activating factor and a natural product isolated from Piper futokadsura was prepared in three steps from 3,4-dimethoxycinnamyl alcohol and allyloxyphenol via rac-(2S,3S)-5-allyl-6-hydroxy-2-(3,4-dime