128261-61-0Relevant academic research and scientific papers
Total Syntheses of Sarcandrolide J and Shizukaol D: Lindenane Sesquiterpenoid [4+2] Dimers
Yuan, Changchun,Du, Biao,Deng, Heping,Man, Yi,Liu, Bo
, p. 637 - 640 (2017)
The syntheses of members of a family of lindenane sesquiterpenoid [4+2] dimers led to the total syntheses of sarcandrolide J and shizukaol D. Inspired by a modified biosynthetic pathway, a cascade featuring furan formation/alkene isomerization/Diels–Alder cycloaddition was devised to construct the congested polycyclic architecture of the target molecules with the correct stereochemistry. This study presents a pioneering synthetic entry to this family of natural products and paves the way for fully exploring their biological functions.
Asymmetric total synthesis of onoseriolide, bolivianine, and isobolivianine
Du, Biao,Yuan, Changchun,Yu, Tianzi,Yang, Li,Yang, Yang,Liu, Bo,Qin, Song
, p. 2613 - 2622 (2014)
In this article, we describe our efforts on the total synthesis of bolivianine (1) and isobolivianine (2), involving the synthesis of onoseriolide (3). The first generation synthesis of bolivianine was completed in 21 steps by following a chiral resolution strategy. Based on the potential biogenetic relationship between bolivianine (1), onoseriolide (3), and β-(E)-ocimene (8), the second generation synthesis of bolivianine was biomimetically achieved from commercially available (+)-verbenone in 14 steps. The improved total synthesis features an unprecedented palladium-catalyzed intramolecular cyclopropanation through an allylic metal carbene, for the construction of the ABC tricyclic system, and a Diels-Alder/intramolecular hetero-Diels-Alder (DA/IMHDA) cascade for installation of the EFG tricyclic skeleton with the correct stereochemistry. Transformation from bolivianine to isobolivianine was facilitated in the presence of acid. The biosynthetic mechanism and the excellent regio- and endo selectivities in the cascade are well supported by theoretical chemistry based on the DFT calculations. From terpenes to terpenes: Two strategies toward the synthesis of bolivianine are described. Based on the modified biogenetic hypothesis, biomimetic total synthesis was evolved and accomplished, involving onoseriolide, bolivianine, and isobolivianine (see figure). Experimental results and DFT calculations support a Diels-Alder/intramolecular hetero-Diels-Alder (DA/IMHDA) cascade leading to bolivianine. In addition, the synthesis features a new Pd-catalyzed intramolecular cyclopropanation. Copyright
Bioinspired total synthesis of bolivianine: A diels-alder/intramolecular hetero-Diels-Alder cascade approach
Yuan, Changchun,Du, Biao,Yang, Li,Liu, Bo
supporting information, p. 9291 - 9294 (2013/07/26)
We report the first total synthesis of bolivanine in a 14-step pathway involving the synthesis of onoseriolide. Our synthesis features a palladium-catalyzed intramolecular cyclopropanation involving an allylic metal carbene and a Diels-Alder/intramolecular hetero-Diels-Alder cascade, allowing the single-step assembly of a tricyclic system with proper configuration. The synthetic efforts validate our modified biogenetic hypothesis and allow us to confirm the absolute configuration of bolivianine.
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.
