311313-44-7Relevant academic research and scientific papers
Progress towards the total synthesis of hamigerans C and D: A direct approach to an elaborated 6-7-5 carbocyclic core
Duquette, Douglas Charles,Jensen, Thomas,Stoltz, Brian Mark
, p. 263 - 267 (2018/02/16)
The hamigeran family of natural products has been the target of numerous synthetic efforts because of its biological activity and interesting structural properties. Herein, we disclose our efforts toward the synthesis of hamigerans C and D, unique among the initially isolated members because of their 6-7-5 carbocyclic core. Our approach directly targets this tricyclic motif by sequential Negishi and Heck coupling reactions, yielding an advanced intermediate with all necessary carbons and sufficient functionality poised for completion of the synthesis of these two natural products.
Synthesis of chiral chromans by the Pd-catalyzed asymmetric allylic alkylation (AAA): Scope, mechanism, and applications
Trost, Barry M.,Shen, Hong C.,Dong, Li,Surivet, Jean-Philippe,Sylvain, Catherine
, p. 11966 - 11983 (2007/10/03)
The Pd-catalyzed asymmetric allylic alkylation (AAA) of phenol allyl carbonates serves as an efficient strategy to construct the allylic C-O bond allowing access to chiral chromans in up to 98% ee. The effect of pH and the influence of olefin geometry, as well as substitution pattern on the ee and the absolute configuration of the chiral chromans were explored in detail. These observations suggest a mechanism involving the cyclization of the more reactive π-allyl palladium diastereomeric intermediate as the enantiodiscriminating step (Curtin-Hammett conditions). This methodology led to the enantioselective synthesis of the vitamin E core, the first enantioselective total synthesis of (+)-clusifoliol and (-)-siccanin, and the synthesis of an advanced intermediate toward (+)-rhododaurichromanic acid A.
Formal synthesis of both atropomers of desertorin C and an example of chirality transfer from a biphenyl axis to a spiro centre and its reverse
Baker, Robert W.,Kyasnoor, Rekha V.,Sargent, Melvyn V.,Skelton, Brian W.,White, Allan H.
, p. 487 - 506 (2007/10/03)
In connection with the synthesis of 4,4′,7,7′-tetramethoxy-5,5′-dimethyl-6,8′-bicoumarin (desertorin C) (11) in enantiopure form, the diastereomeric ratios of the products of the reactions between 2-isopropyloxy-6-methoxy-4-methylphenylmagnesium bromide (24) and (4S)-4-isopropyl-2-(2,3,5-trimethoxyphenyl)-4,5-dihydrooxazole (23), between 2,4-dimethoxy-6-methylphenylmagnesium bromide (37) and (4S)-4-isopropyl-2-(2,3-dimethoxy-5-methylphenyl)-4,5-dihydrooxazole (36), and between 2,4-dimethoxy-6-(t-butyldimethylsilyloxy)methylphenyl-magnesium bromide (46) and the oxazole (36) were explored. The major product of the last mentioned reaction was converted into (S,4S)-4-isopropyl-2-(2′-hydroxymethyl-4′,6,6′-trimethoxy-4- methyl-1,1′-biphenyl-6-yl)-4,5-dihydroxazole (49), the axial configuration of which was confirmed by single crystal X-ray structural determination. The similar product (S,4S)-2-(2′,4′,6-trimethoxy-4,6′-dimethyl-1,1′- biphenyl-6-yl)-4,5-dihydrooxazole (43) was converted into (S)-1-(2,4′,6′-trimethoxy-4,6′-biphenyl-2-yl)ethanone (57) which furnished (S)-1-(2′,4′,6-trimethoxy-4,6′-dimethyl-1,1′-biphenyl-2- yl)acetamide (58) (43%) and (S)-2,7′-dimethoxy-3′,5′,6-trimethylspiro[cyclohexa-2,5-diene- 1,1′-(1H)isoindole]-4-one (61) (30%) on Schmidt rearrangement. The dienone (61) on reduction and methylation regenerated the ketone (57). The methodology of Lipschutz was adapted for the synthesis of both enantiomers of 1,1′-(2′,4-dihydroxy-6,6′-dimethoxy-2,4′- dimethylbiphenyl-3,3′-diyl)bisethanone (32) and (83) which constitutes a formal synthesis of both enantiomers of desertorin C. CSIRO 2000.
A formal synthesis of both atropenantiomers of desertorin C
Kyasnoor, Rekha V.,Sargent, Melvyn V.
, p. 2713 - 2714 (2007/10/03)
Asymmetric synthesis of both enantiomers of 1,1'-(2',4-dihydroxy-6,6'-dimethoxy-2,4'-dimethylbiphenyl-3,3'-diyl) -bisethanone allows the formal synthesis of both enantiomers of 4,4',7,7'-tetramethoxy-5,5'-dimethyl-6,8'- bicoumarin (desertorin C).
