6302-93-8Relevant articles and documents
Dithioacetalization or thioetherification of benzyl alcohols using 9-mesityl-10-methylacridinium perchlorate photocatalyst
Pramanik, Milan,Choudhuri, Khokan,Mathuri, Ashis,Mal, Prasenjit
supporting information, p. 10211 - 10214 (2020/09/21)
We report herein the use of 9-mesityl-10-methylacridinium perchlorate as the visible-light photocatalyst for dithioacetalization or thioetherification of benzyl alcohols in one pot using aerial dioxygen as a terminal oxidant. EPR analysis and Stern-Volmer
Enantioselective synthesis of natural dibenzylbutyrolactone lignans (-)-enterolactone, (-)-hinokinin, (-)-pluviatolide, (-)-enterodiol, and furofuran lignan (-)-eudesmin via tandem conjugate addition to γ-alkoxybutenolides1,2
Van Oeveren,Jansen,Feringa
, p. 5999 - 6007 (2007/10/02)
A general and efficient method is described for the asymmetric synthesis of a variety of liguans. 5-(Menthyloxy)-2(5H)-furanones 5 proved to be excellent chiral synthons in this respect and could be transformed with complete stereoselectivity into a number of lignans. The addition of lithiated dithianes 7 to enantiomerically pure butenolides 5 was followed by quenching of the resulting lactone enolate anions with a benzylbromide (9) or with an aldehyde (6). This tandem addition quenching procedure gave the diastereomerically pure adducts 11, 26, or 27 in 50-67% yield, with a carbon skeleton as found in most natural lignans. As examples of the wide applicability of this method, the syntheses of the enantiomerically pure natural lignans (-)-hinokinin (23b), (-)-enterolactone (24a), (-)-pluviatolide (24c), and (-)-enterodiol (25) in overall yields of 29-37% from 5a and (-)eudesmin (30) in 16% overall yield from 5b are described.
General Conjugate-Addition Method for the Synthesis of Enantiomerically Pure Lignans. Total Synthesis of (-)- and (+)-Burseran, (-)-Dehydroxycubebin, (-)-Trichostin, (-)-Cubebin, (-)-5''-Methoxyhinokinin, and (-)-Hinokinin
Rehnberg, Nicola,Magnusson, Goeran
, p. 4340 - 4349 (2007/10/02)
Conjugate addition of benzylic diphenyldithioacetal anions to enantiomerically pure (-)-(2R)-and (+)-(2S)-(benzyloxy)-2,5-dihydro-4-furan (2 r and 2 s) gave complete lignan skeletons of the dibenzylbutane class.Desulfurization followed by hydrogenolysis and, when appropriate, oxidation gave the title enantiomerically pure > 99 percent ee) lignans 45 - 50 in 24 - 35 percent overall yields from 2 r and 2 s.