- Chiron approach for the total synthesis of (+)-synargentolide B
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A concise and efficient chiron approach for the total synthesis of natural product synargentolide B was achieved in 10 steps with overall yields of 11.3% from D-mannitol and L-ethyl lactate. The key reactions included anti-Barbier allylation, cross-metathesis, and an intramolecular Yamaguchi esterification.
- Liu, Jun,Gao, Yangguang,Wang, Linlin,Du, Yuguo
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p. 6443 - 6447
(2017/10/09)
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- Total synthesis of marine natural products separacenes A and B
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A short and convergent route for the stereoselective total synthesis of separacenes A and B has been developed using (+)-methyl d-lactate and d-(-)-tartaric acid as the chiral pools. The characteristic features of this synthesis include the Trost-Rychnovsky alkyne rearrangement to construct the C7-C9 conjugated diene, the Horner-Wadsworth-Emmons olefination to form the C5-C6 and C11-C12 olefins and the Corey-Bakshi-Shibata reaction to install the C-13 hydroxy functionality.
- Das, Subhendu,Goswami, Rajib Kumar
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p. 4842 - 4850
(2017/07/10)
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- Tandem ring-closing/cross-metathesis approach for the synthesis of synargentolide B and its stereoisomers
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The stereoselective syntheses of synargentolide B and its three stereoisomers have been accomplished from L-(+)- and D-(-)-diethyl tartrates, D-ribose, and D-mannitol as chiral pool starting materials. The key step was a tandem ring-closing/cross-metathes
- Sabitha, Gowravaram,Shankaraiah, Kontham,Yadav, Jhillu S.
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p. 4870 - 4878
(2013/08/23)
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- Epi -, Epoxy-, and C2-modified bengamides: Synthesis and biological evaluation
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With the objective of investigating the influence of structural modifications of the polyketide chain of the bengamides upon their antitumoral activities, we targeted the preparation of bengamide E analogues with modification of the stereochemistry at C-2 and at C-3, the substituent at the C-2 position, and the presence of oxirane rings. For the synthesis of these analogues, a new synthetic method for asymmetric epoxidation, developed in our laboratories, was employed utilizing the chiral sulfonium salts 22 and 23. In order to access 2-epi-bengamide E from these epoxy amides, a synthetic methodology, developed by Miyashita, allowed an oxirane-ring-opening reaction with a double inversion of the configuration. Alternatively, an aldol reaction provided access to the same analogue in a shorter and more efficient manner. Finally, biological evaluation of all of these bengamide E analogues demonstrated that the polyketide chain is essential for the antitumor activity of these natural products, not being amenable to structural or configurational modifications.
- Sarabia, Francisco,Martín-Gálvez, Francisca,García-Ruiz, Cristina,Sánchez-Ruiz, Antonio,Vivar-García, Carlos
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p. 5239 - 5253
(2013/07/26)
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- Stereoselective and facile total synthesis of (+)-goniodiol, a styryllactone from carbohydrates
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The stereoselective synthesis of (+)-goniodiol, a cytotoxic styryllactone, has been accomplished in 10 steps starting from inexpensive and readily available d-manitol and δ-gluconolactone involving the direct and straightforward reaction conditions of Gri
- Yadav, Jhillu Singh,Das, Saibal,Mishra, Anand Kumar
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experimental part
p. 2443 - 2447
(2011/02/22)
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- Doubly diastereoselective conjugate addition of homochiral lithium amides to homochiral α,β-unsaturated esters containing cis- and trans-dioxolane units
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As part of a long-term goal directed towards the ab initio asymmetric synthesis of unnatural amino sugars, the doubly diastereoselective conjugate addition reactions of the antipodes of lithium N-benzyl-N-(α-methylbenzyl) amide to a range of homochiral α,β-unsaturated esters containing cis- and trans-dioxolane units was investigated. These reactions resulted in "matching" and "mismatching" effects. In the "matched" cases a single diastereoisomer of the corresponding β-amino ester (containing three contiguous stereocentres) is produced. Upon conjugate addition to a homochiral α,β-unsaturated ester containing a cis-dioxolane unit, in the "mismatched" case it is the stereocontrol of the substrate which is dominant over that of the lithium amide, whilst upon addition to homochiral α,β-unsaturated esters containing a trans-dioxolane unit the stereocontrol of the homochiral lithium amide is dominant. Hydrogenolytic N-deprotection of the β-amino ester products of conjugate addition gives access to polyoxygenated β-amino acid derivatives.
- Davies, Stephen G.,Durbin, Matthew J.,Goddard, Euan C.,Kelly, Peter M.,Kurosawa, Wataru,Lee, James A.,Nicholson, Rebecca L.,Price, Paul D.,Roberts, Paul M.,Russell, Angela J.,Scott, Philip M.,Smith, Andrew D.
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supporting information; experimental part
p. 761 - 776
(2009/06/19)
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- Total syntheses of (+)-7-epi-goniofufurone, (+)-goniopypyrone and (+)-goniofufurone from a common precursor
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Total syntheses of (+)-7-epi-goniofufurone, (+)-goniopypyrone and (+)-goniofufurone have been achieved from an advanced common precursor formed from d-(+)-mannitol by changing the carbinol protection profile. The Royal Society of Chemistry.
- Yadav, Veejendra K.,Agrawal, Divya
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p. 5232 - 5234
(2008/09/20)
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- Total synthesis of amphidinolide E and amphidinolide E stereoisomers
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Four amphidinolide E stereoisomers, amphidinolide E (1), 2-epi-amphidinolide E (2), 19-epi-amphidinolide E (3), and 2-epi-19-epi-amphidinolide E (4), have been synthesized via the judicious union of aldehyde 5, allylsilanes 7 or 8, acids 9 or 10, and viny
- Va, Porino,Roush, William R.
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p. 5768 - 5796
(2008/02/02)
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- Total synthesis of amphidinolide E
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A convergent and highly stereocontrolled synthesis of amphidinolide E (1) has been accomplished. The synthesis features a highly diastereoselective (>20:1) BF3·Et2O promoted [3+2] annulation reaction between aldehyde 3 and allylsilan
- Va, Porino,Roush, William R.
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p. 15960 - 15961
(2007/10/03)
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- Synthesis of (+)-goniothalesdiol and (+)-7-epi-goniothalesdiol
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A total synthesis of (+)-goniothalesdiol, a 3,4-dihydroxy-2,5-disubstituted tetrahydrofuran isolated from Goniothalamus borneensis (Annonaceae), and its 7-epimer is reported using oxycarbonylation methodology for construction of polyhydroxylated substitut
- Babjak, Matej,Kapitán, Peter,Gracza, Tibor
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p. 2471 - 2479
(2007/10/03)
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- Total synthesis of bengamide E and analogues by modification at C-2 and at terminal olefinic positions
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The total synthesis of the natural product Bengamide E, one of the members of a new class of antitumor natural products of marine origin, is reported based on a convergent and flexible synthetic route featuring an oxirane ring-opening reaction and an olefin cross metathesis. In a similar way, analogues structurally modified at C-2 and at the terminal vinyl positions were prepared by introduction of various nucleophiles and alkyl substituents during the epoxide opening and the olefin cross metathesis steps, respectively. These studies demonstrate the validity of our synthetic strategy, although they reveal some problems associated with the olefin cross metathesis, whose efficiency depends on the substituent at the C-2 position as well as the steric environment of the alkene.
- Sarabia, Francisco,Sanchez-Ruiz, Antonio
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p. 9514 - 9520
(2007/10/03)
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- A stereoselective total synthesis of (-)-rishitin
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A new synthesis of (-)-rishitin (1) is reported, starting with chiral pool molecules. The crucial step is a stereoselective vinyl radical cyclization, which gives a 10:1 ratio of 21 to 22.
- Chen, Jiong,Marx, John N.
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p. 1889 - 1892
(2007/10/03)
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- Double asymmetric iodoamination; synthesis of C2 symmetric and meso-amino alcohols
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Alkenic diols 2 and 14 are iodocyclized providing dihydro-1,3-oxazine 3 and dihydrooxazole 15 in 90 and 93% de, respectively, which are precursors of various C2 symmetric and meso-amino alcohols.
- Kang, Sung Ho,Ryu, Do Hyun
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p. 355 - 356
(2007/10/03)
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