20303-60-0Relevant articles and documents
Efficient synthesis of the anticancer β-elemene and other bioactive elemanes from sustainable germacrone
Barrero, Alejandro F.,Herrador, M. Mar,Quilez Del Moral, Jose F.,Arteaga, Pilar,Meine, Niklas,Perez-Morales, M. Carmen,Catalan, Julieta V.
experimental part, p. 1118 - 1125 (2011/04/15)
Highly efficient preparations of anticancer β-elemene and other bioactive elemanes were carried out using the natural product germacrone as a renewable starting material. The syntheses were achieved in only 3-5 steps with excellent overall yields (43-54%). An enantioselective approach to these molecules is also described
The Use of 4,4-Disubstituted Nopinones for Natural-Product Synthesis. Synthesis of Elemanoid Sesquiterpenes
Kato, Michiharu,Watanabe, Masataka,Vogler, Bernhard,Awen, Bahlul Z.,Masuda, Yoshiaki,et al.
, p. 7071 - 7076 (2007/10/02)
A general and convenient synthetic route to 4,4-disubstituted nopinones 14 from (+)-nopinone (1) is developed and applied to the asymmetric synthesis of some representative elemanoid sesquiterpenes.Phenylsulfenylation of 1 provided sulfide 6 in high yields.A convenient transformation of 6 to 3-(phenylsulfonyl)-4,4-disubstituted-nopinones 13 was accomplished by (i) m-CPBA oxidation of a sulfide compound followed by the Pummerer rearrangement and (ii) the conjugate addition of carbon nucleophiles to the resulting enones, 6 -> 8 -> 9 and 9 -> 10, 11 -> 13.Subsequent reductive desulfurization of the adducts 13 provided 14 in good overall yield from 1.Bicyclic ketones 14 are envisioned as promising intermediates for natural product synthesis.As examples, syntheses of two elemanoid sesquiterpenes, β-elemenone (16) and eleman-8β,12-olide (17) in optically active form from (1R,4S,5S)-4,6,6-trimethyl-4-vinylbicycloheptan-2-one (14a) were carried out.
A Key Intermediate for the Chiral Synthesis of Elemanoids. Synthesis of (+)-β-Elemenone
Kato, Michiharu,Vogler, Bernhard,Tooyama, Youichi,Yoshikoshi,Akira
, p. 151 - 154 (2007/10/02)
(1R,5S)-3-Phenylsulfenyl-6,6-dimethylbicycloheptanone obtained from (+)-nopinone was transformed into (1R,4S,5S)-4-methyl-4-vinylbicycloheptan-2-one, whose cyclobutane ring was cleaved with BF3*EtO2-Zn(OAc)2 in acetic anhydride to provide (4S,5S)-1-acetoxy-4-isopropenyl-5-methyl-5-vinyl-1-cyclohexene (5), the key intermediate, in a highly regio- and stereoselective manner.Regioselective introduction of a three-carbon unit to 5 with acetone followed by dehydration yielded (+)-β-elemenone.