- Dictating Thermodynamic Control through Tethering: Applications to Stereoselective Bis-Spiroketal Synthesis
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Approaches to stereocontrol that invoke thermodynamic control fail when two or more potential products are energetically similar, but rational structural perturbations can be employed to break the energetic degeneracy and provide selective transformations. This manuscript illustrates that tethering is an effective approach for the stereoselective construction of bis-spiroketals with thermodynamically similar stereoisomers, providing a new approach to set remote stereocenters and prepare complex structures that have not previously been accessed stereoselectively.
- Asari, Austin H.,Floreancig, Paul E.
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- Synthesis of Aminoallenes via Selenium-π-Acid-Catalyzed Cross-Coupling of N-Fluorinated Sulfonimides with Simple Alkynes
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The facile synthesis of aminoallenes, accomplished by a selenium-π-acid-catalyzed cross-coupling of an N-fluorinated sulfonimide with simple, non-activated alkynes, is reported. Until now, aminoallenes were difficult to be accessed by customary means, inasmuch as pre-activated and, in part, intricate starting materials were necessary for their synthesis. In sharp contrast, the current study shows that ordinary internal alkynes can serve as simple and readily available precursors for the construction of the aminoallene motif. The operating reaction conditions tolerate numerous functional groups such as esters, nitriles, (silyl)ethers, acetals, and halogen substituents, furnishing the target compounds in up to 86 % yield.
- Rode, Katharina,Ramadas Narasimhamurthy, Poorva,Rieger, Rene,Kr?tzschmar, Felix,Breder, Alexander
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supporting information
p. 1720 - 1725
(2021/03/16)
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- SYNTHESIS OF DELTA 12-PGJ3 AND RELATED COMPOUNDS
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In one aspect, the present invention provides novel derivatives of Δ12-PGJ3 and modular synthetic pathways to obtaining Δ12-PGJ3 and derivatives thereof. In some aspects, the present derivatives of Δ12-PGJ3 are useful as chemotherapeutic agents. The present disclosure also describes compositions of these derivatives as well as methods of use of the derivatives thereof.
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Page/Page column 133
(2015/04/15)
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- Cryptocaryol Structure-Activity Relationship Study of Cancer Cell Cytotoxicity and Ability to Stabilize PDCD4
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The synthetic cryptocaryols A and B and a series of their analogues have been evaluated for their cytotoxicity and their ability to stabilize the tumor suppressor PDCD4. Cytotoxicities in the 3 to 30 μM range were found. Both the cytotoxicity and PDCD4 stabilizing ability were tolerant of large stereochemical changes to the molecule. Co-dosing studies with cryptocaryols A and B and several known cancer drugs showed no measuable enhancement in cancer drug cytotoxicity.
- Cuccarese, Michael F.,Wang, Yanping,Beuning, Penny J.,O'Doherty, George A.
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supporting information
p. 522 - 526
(2014/06/09)
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- Sustainable, mild and efficient p-methoxybenzyl ether deprotections utilizing catalytic DDQ
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A procedure for the selective deprotection of p-methoxybenzyl ethers using catalytic amounts of DDQ and of sodium nitrite, with oxygen as the terminal oxidant, is reported.
- Walsh, Katie,Sneddon, Helen F.,Moody, Christopher J.
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p. 7380 - 7387
(2017/09/13)
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- Cryptocaryols A and B: Total syntheses, stereochemical revision, structure elucidation, and structure-activity relationship
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The first total syntheses and structural elucidation of cryptocaryol A and cryptocaryol B were achieved in 23 and 25 linear steps, respectively. The synthesis relied on the use of a key pseudo-Cs symmetric pentaol intermediate, which in a stere
- Wang, Yanping,O'Doherty, George A.
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supporting information
p. 9334 - 9337
(2013/07/25)
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- A convenient approach for the deprotection and scavenging of the PMB group using POCl3
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A convenient and high yielding approach for the deprotection and scavenging of the p-methoxybenzyl (PMB) group in PMB ethers and PMB esters was developed using POCl3 as the reagent. 4-Methoxybenzyl chloride, a starting material used for the preparation of PMB ethers and esters was regenerated in the deprotection step. This mild and selective procedure tolerates several acid sensitive functional groups. The Royal Society of Chemistry 2013.
- Ilangovan, Andivelu,Saravanakumar, Shanmugasundar,Malayappasamy, Subramani,Manickam, Govindaswamy
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p. 14814 - 14828
(2013/09/02)
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- Stereoselective synthesis of conjugated trienols from allylic alcohols and 1-iodo-1,3-dienes
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The stereoselective synthesis of conjugated trienes has been achieved from allylic alcohols and 1-iodo-1,3-dienes using Pd(OAc)2/AgOAc.
- Brandt, Damien,Bellosta, Veronique,Cossy, Janine
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supporting information
p. 5594 - 5597,4
(2012/12/12)
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- Enantioselective synthesis of herbarumin III by using a chelation-controlled reduction
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The total synthesis of herbarumin III (1) was achieved via an alkynide ion addition onto a chiral aldehyde and LiAlH4/LiI reduction as key steps (Scheme 2).
- Sabitha, Gowravaram,Srinivas, Chitti,Maruthi, Chittapragada,Yadav, Jhillu Singh
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scheme or table
p. 1634 - 1640
(2010/12/24)
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- Cascade resulting in the reductive ethynylation of aldehydes: Dissection of its components
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A mild and efficient two-carbon homologation of aldehydes exploiting multiple modes of KOt-Bu was developed. This process involves a sequential Peterson allenylation/allene-alkyne isomerization/ protodesilylation in a single-flask operation. The differential roles played by the various elements of the process were demonstrated through dissection experiments.
- Lee, Dongjoo,Danishefsky, Samuel J.
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supporting information; experimental part
p. 4427 - 4430
(2010/06/14)
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- Total synthesis of (±)-stemonamide and (±)-isostemonamide
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Two different approaches to the alkaloids stemonamide and isostemonamide using N-acyliminium chemistry are described. The approach using an aldol spirocyclization to construct the second contiguous spirocenter was successful. The total synthesis of these
- Kende, Andrew S,Martin Hernando, Jose I,Milbank, Jared B.J
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- The biomimetic construction of fused cyclic polyethers
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The formation of fused cyclic ethers by biomimetic synthesis was demonstrated. The one-pot successive ring-expansion reactions of bromo diepoxides were investigated by regarding the epoxy groups as the nucleophiles for the intramolecular cationic carbons to obtain the fused cyclic ethers.
- Hayashi, Nobuyuki,Fujiwara, Kenshu,Murai, Akio
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p. 12425 - 12468
(2007/10/03)
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