Construction of Single Stereocenters

2017 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Asymmetric Hydrogenation ◽  
Bifunctional Catalyst ◽  
Allyl Ether ◽  
University Of Texas ◽  
Iridium Catalysis ◽  
Enantioselective Epoxidation ◽  
Institute Of Technology ◽  
The University ◽  
Academy Of Sciences ◽  
University Of Manchester

Haifeng Du at the Chinese Academy of Sciences reported (J. Am. Chem. Soc. 2013, 135, 6810) the borane-catalyzed asymmetric hydrogenation of imine 1 to 2 using the diene 3 as a chiral ligand for boron. A single-enzyme cascade for the reductive transam­ination of acetophenone 4 with amine 5 to produce enantiopure sec-phenethylamine 6 was developed (Chem. Commun. 2013, 49, 161) by Per Berglund at the KTH Royal Institute of Technology in Sweden. A group at Boehringer Ingelheim in Ridgefield, Connecticut, led by Jonathan T. Reeves, disclosed (J. Am. Chem. Soc. 2013, 135, 5565) a procedure for the addition of DMF anion to N-sulfinyl imine 7 to furnish tert-leucine amide 8 with high diastereoselectivity. The tertiary carbinamine 10 was synthesized (Org. Lett. 2013, 15, 34) via the carbolithiation/rearrangement of vinyl­urea 9 as reported by Jonathan Clayden at the University of Manchester. Gregory C. Fu at Caltech reported (Angew. Chem. Int. Ed. 2013, 52, 2525) that the chiral phosphine 12 catalyzed the enantioselective addition of trifluoroacetamide to allene 11 to produce γ-amino ester 13 in enantioenriched form. Adeline Vallribera at the Autonomous University of Barcelona found (Org. Lett. 2013, 15, 1448) that a euro­pium pybox complex effected the highly enantioselective α-amination of β-ketoester 14 to generate 15 on the way to the Parkinson’s disease co-drug L-carbidopa. Hisashi Yamamoto at the University of Chicago and Chubu University reported (J. Am. Chem. Soc. 2013, 135, 3411) that a halfnium(IV) complex of the bishydroxamic acid 17 catalyzed the enantioselective epoxidation of the tertiary homoallylic alcohol 16 to 18. The rearrangement of the allylic carbonate 19 to produce allyl ether 21 with high ee under iridium catalysis in the presence of ligand 20 was disclosed (Org. Lett. 2013, 15, 512) by Hyunsoo Han at the University of Texas, San Antonio. The asymmetric vinylogous aldol reaction of 3-methyl-2-cyclohexen-1-one 22 and α-keto ester 23 to furnish tertiary carbinol 25 using the bifunctional catalyst 24 was developed (Org. Lett. 2013, 15, 220) by Paolo Melchiorre at ICREA and ICIQ in Spain.

Stereocontrolled Construction of Arrays of Stereogenic Centers: The Mullins Synthesis of (-)-Lasiol

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Aldol Condensation ◽  
Catalyst System ◽  
Geometric Isomer ◽  
Ni Catalyst ◽  
University Of Texas ◽  
Enantioselective Epoxidation ◽  
Institute Of Technology ◽  
Tandem Cyclization ◽  
Catalyst Systems ◽  
The University

Hisashi Yamamoto of the University of Chicago devised (J. Am. Chem. Soc. 2010, 132, 7878) catalyst systems for the enantioselective epoxidation of a Z -homoallylic alcohol 1. Michael J. Krische of the University of Texas developed (J. Am. Chem. Soc. 2010, 132, 1760) a catalyst system for the highly stereoselective addition of the vinyl acetal 5 to an aldehyde 4. Joëlle Prunet of the University of Glasgow showed (Tetrahedron Lett. 2010, 51, 256) that the tandem cyclization/Julia olefination from 7 also proceeded with high stereocontrol. Professor Yamamoto established (J. Am. Chem. Soc. 2010, 132, 5354) that depending on conditions, the aldol condensation of 10 could be directed selectively toward either diastereomer of the product 12. James M. Takacs of the University of Nebraska effected (J. Am. Chem. Soc. 2010, 132, 1740) the enantioselective hydroboration of 10. The other geometric isomer of 10 gave the alternative diastereomer of 12, also with high ee. John Limanto and Shane W. Krska of Merck Process optimized (Organic Lett . 2010, 12, 512) the dynamic kinetic reduction of 13 , giving 14 with excellent diastereocontrol. Professor Krische extended (J. Am. Chem. Soc. 2010, 132, 4562) his reductive homologation to the (racemic) carbonate 15, delivering 16 with excellent dr and ee. Hirokazu Urabe of the Tokyo Institute of Technology showed (Organic Lett. 2010, 12, 1012) that a Grignard reagent under iron catalysis opened the epoxide 17, readily available by Jørgensen-Cordova epoxidation followed by homologation, with clean inversion and high regiocontrol. Fraser F. Fleming of Duquesne University developed (Organic Lett. 2010, 12, 3030) a general route to quaternary alkylated centers by alkylation of nitriles such as 19. Shigeki Matsunaga and Masakatsu Shibasaki of the University of Tokyo devised (J. Am. Chem. Soc. 2010, 132, 3666) a Ni catalyst for the stereoselective conjugate addition of the lactam 22 to a nitroalkene 21. Aldehydes can also be added to nitroalkenes with high dr and ee, as illustrated by the conversion of 24 to 26 reported (J. Am. Chem. Soc. 2010, 132, 50) by Bukuo Ni of Texas A&M University, Commerce.

Functional Group Oxidation and Reduction

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Direct Conversion ◽  
University Of Mississippi ◽  
Ru Catalyst ◽  
Mo Catalyst ◽  
University Of Arizona ◽  
Institute Of Technology ◽  
Diastereoselective Reduction ◽  
The University ◽  
University Of Manchester ◽  
Mediated Reduction

Debabrata Maiti of the Indian Institute of Technology Bombay found (Chem. Commun. 2012, 48, 4253) that the relatively inexpensive Pd(OAc)2 effectively catalyzed the decarbonylation of an aldehyde 1 to the hydrocarbon 2. Hui Lou of Zhejiang University used (Adv. Synth. Catal. 2011, 353, 2577) a Mo catalyst to effect reduction of the ester 3 to the hydrocarbon 4, with retention of all the skeletal carbons. Jon T. Njardarson of the University of Arizona showed (Chem. Commun. 2012, 48, 7844) that the allylic ether 5 could be reduced with high regioselectivity to give 6. José Barluenga and Carlos Valdés of the Universidad de Oviedo effected (Angew. Chem. Int. Ed. 2012, 51, 5950) the direct conversion of a ketone 7 to the azide 8. Although no cyclic ketones were included in the examples, there is a good chance that this will be the long-sought diastereoselective reduction of a cyclohexanone to the equatorial amine. Hideo Nagashima of Kyushu University reduced (Chem. Lett. 2012, 41, 229) the acid 9 directly to the aldehyde 1 using a ruthenium catalyst with the bis silane 10. Georgii I. Nikonov of Brock University described (Adv. Synth. Catal. 2012, 354, 607) a similar Ru-mediated silane reduction of an acid chloride to the aldehyde. Professor Nagashima used (Angew. Chem. Int. Ed. 2012, 51, 5363) his same Ru catalyst to reduce the ester 11 to the protected amine 12. Shmaryahu Hoz of Bar-Ilan University used (J. Org. Chem. 2012, 77, 4029) photostimulation to promote the SmI2-mediated reduction of a nitrile 13 to the amine 14. Bakthan Singaram of the University of California, Santa Cruz effected (J. Org. Chem. 2012, 77, 221) the same transformation with InCl3/NaBH4. David J. Procter of the University of Manchester described (J. Org. Chem. 2012, 77, 3049) what promises to be a general method for activating Sm metal to form SmI2. Mark T. Hamann of the University of Mississippi directly reduced (J. Org. Chem. 2012, 77, 4578) the nitro group of 15 to the alkylated amine 16. Cleanly oxidizing aromatic methyl groups to the level of the aldehyde without overoxidation has been a challenge.

Functional Group Transformations

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Gold Catalyst ◽  
Sulfonyl Chloride ◽  
Allylic Alcohol ◽  
West Virginia University ◽  
Israel Institute ◽  
University Of Texas ◽  
Amino Amide ◽  
Cu Catalyst ◽  
Institute Of Technology ◽  
The University

Mark Gandelman of the Technion–Israel Institute of Technology devised (Adv. Synth. Catal. 2011, 353, 1438) a protocol for the decarboxylative conversion of an acid 1 to the iodide 3. Doug E. Frantz of the University of Texas, San Antonio effected (Angew. Chem. Int. Ed. 2011, 50, 6128) conversion of a β-keto ester 4 to the diene 5 by way of the vinyl triflate. Pei Nian Liu of the East China University of Science and Technology and Chak Po Lau of the Hong Kong Polytechnic University (Adv. Synth. Catal. 2011, 353, 275) and Robert G. Bergman and Kenneth N. Raymond of the University of California, Berkeley (J. Am. Chem. Soc. 2011, 133, 11964) described new Ru catalysts for the isomerization of an allylic alcohol 6 to the ketone 7. Xiaodong Shi of West Virginia University optimized (Adv. Synth. Catal. 2011, 353, 2584) a gold catalyst for the rearrangement of a propargylic ester 8 to the enone 9. Xue-Yuan Liu of Lanzhou University used (Adv. Synth. Catal. 2011, 353, 3157) a Cu catalyst to add the chloramine 11 to the alkyne 10 to give 12. Kasi Pitchumani of Madurai Kamaraj University converted (Org. Lett. 2011, 13, 5728) the alkyne 13 into the α-amino amide 15 by reaction with the nitrone 14. Katsuhiko Tomooka of Kyushu University effected (J. Am. Chem. Soc. 2011, 133, 20712) hydrosilylation of the propargylic ether 16 to the alcohol 17. Matthew J. Cook of Queen’s University Belfast (Chem. Commun. 2011, 47, 11104) and Anna M. Costa and Jaume Vilarrasa of the Universitat de Barcelona (Org. Lett. 2011, 13, 4934) improved the conversion of an alkenyl silane 18 to the iodide 19. Vinay Girijavallabhan of Merck/Kenilworth developed (J. Org. Chem. 2011, 76, 6442) a Co catalyst for the Markovnikov addition of sulfide to an alkene 20. Hojat Veisi of Payame Noor University oxidized (Synlett 2011, 2315) the thiol 22 directly to the sulfonyl chloride 23. Nicholas M. Leonard of Abbott Laboratories prepared (J. Org. Chem. 2011, 76, 9169) the chromatography-stable O-Su ester 25 from the corresponding acid 24.

scholarly journals Valentine Louis Telegdi. 11 January 1922 — 8 April 2006

2009 ◽  
Vol 55 ◽  
pp. 291-304
Author(s):  
Laurie M. Brown
Keyword(s):  
Academic Career ◽  
University Of Chicago ◽  
National Academy Of Sciences ◽  
Wolfgang Pauli ◽  
Electromagnetic Interactions ◽  
Federal Institute ◽  
Experimental Physicist ◽  
Institute Of Technology ◽  
The University ◽  
Academy Of Sciences

Valentine Telegdi was an outstandingly original experimental physicist who contributed greatly to our understanding of the weak and electromagnetic interactions of elementary particles. Outspoken and colourful in expression, Telegdi (usually called ‘Val’) had the reputation of being a ‘conscience of physics’, known for his incisive and sometimes acerbic wit. In this respect he was reminiscent of Wolfgang Pauli, one of his teachers, whom he greatly admired. However, Val could be warm and caring to friends, professional associates and students. After receiving his doctorate from the Swiss Federal Institute of Technology (ETH) in Zurich in 1950, he began his academic career at the University of Chicago in 1951, and his reputation grew rapidly. In 1968 he was elected to the National Academy of Sciences. In 1972 the University of Chicago appointed him as the first Enrico Fermi Distinguished Service Professor of Physics.

scholarly journals Meet the APSA Council and Officers

2012 ◽  
Vol 45 (01) ◽  
pp. 151-154
Keyword(s):  
Harvard University ◽  
University Of California ◽  
Massachusetts Institute ◽  
University Of Southern California ◽  
Massachusetts Institute Of Technology ◽  
New Members ◽  
Reed College ◽  
Institute Of Technology ◽  
The University ◽  
University Of Manchester

As noted in the October issue ofPS, G. Bingham Powell, Jr., the Marie E .and Joseph C. Wilson Professor of Political Science at the University of Rochester, became APSA's 108th president on September 4, 2011, at the close of the APSA Annual Meeting. Eight new members of the APSA council were elected fall 2011. The new members are Paul Gronke, Reed College; Ange-Marie Hancock, University of Southern California; David A. Lake, University of California, San Diego; Taeku Lee, University of California, Berkeley; Kenneth J. Meier, Texas A&M University; Kathleen Thelen, Massachusetts Institute of Technology; Stephen M. Walt, Harvard University; and Angelia R. Wilson, University of Manchester.

scholarly journals Reviewer Acknowledgements

2018 ◽  
Vol 4 (1) ◽  
pp. 105
Author(s):  
Ellery Willianms
Keyword(s):  
Bulgarian Academy ◽  
University Of Technology ◽  
National Economic ◽  
Auditor General ◽  
The University ◽  
Academy Of Sciences ◽  
University Of Manchester ◽  
Universiti Utara Malaysia ◽  
Business And Management

Business and Management Studies (BMS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether BMS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 4, Number 1 Abdul-Kahar Adam, University of Education, Winneba, GhanaAndrzej Niemiec, Poznań University of Economics and Business, PolandAsad Ghalib, The University of Manchester, UKAshford Chea, Benedict College, USAComite Ubaldo, University of Calabria, ItalyDaiane Miranda Freitas, FACISA/Univicosa, BrazilDalia Susniene, Kaunas University of Technology, LithuaniaFlorin Peci, University of Peja, KosovoGabriela O. Chiciudean, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, RomaniaJulia Stefanova, Bulgarian Academy of Sciences, BulgariaKonstantinos N. Malagas, University of the Aegean, GreeceLucie Andreisová, University of Economics in Prague, CzechMike Rayner, University of Portsmouth, UKMythili Kolluru, College of Banking and Financial Studies, OmanOleksandr Mosin, National Mining University, UkraineOlha Komelina, Yuri Kondratyuk University, UkraineRashedul Hasan, International Islamic University Malaysia, MalaysiaRegina Lenart-Gansiniec, Jagiellonian University, PolandRocsana Tonis, Spiru Haret University, RomaniaSammy Kimunguyi, Office of The Auditor-General, KenyaTetiana Paientko, Kyiv National Economic Univercity, UkraineUmair Akram, Beijing Univ Posts & Telecommun, PAKISTANWaeibrorheem Waemustafa, Universiti Utara Malaysia, MalaysiaYanzhe Zhang, University of Canberra, AustraliaZeki Atıl Bulut, Dokuz Eylul University, Turkey Ellery WillianmsEditorial AssistantOn behalf of,The Editorial Board of Business and Management StudiesRedfame Publishing9450 SW Gemini Dr. #99416Beaverton, OR 97008, USAURL: http://bms.redfame.com

Richard Ernst Meyer 1919 - 2008

2010 ◽  
Vol 21 (1) ◽  
pp. 75 ◽  
Author(s):  
R. J. Stalker ◽  
E. Nicole Meyer
Keyword(s):  
Fluid Motion ◽  
Wave Theory ◽  
Federal Institute ◽  
The Usa ◽  
Institute Of Technology ◽  
The University ◽  
University Of Manchester ◽  
Aircraft Production ◽  
Supersonic Aerodynamics ◽  
Mathematical Physicist

Richard E. Meyer was a mathematical physicist who specialized in the physics of fluid motion. His research career began with his doctorate at the Swiss Federal Institute of Technology, followed by a brief period of employment with the English Ministry of Aircraft Production. He then went to the University of Manchester, where he made his first major research contributions. In 1953 he left Manchester for the University of Sydney. By this time he was established as a theoretical supersonic aerodynamicist and he continued with this work as well as assuming the responsibilities of a research group leader. In 1957 he went to the USA and remained there for the rest of his life, essentially abandoning supersonic aerodynamics in favour of water-wave theory. His work was marked by an ability to analyse the approach to limiting conditions, or singularities, in models of physical processes. From the 1970s, he focused increasingly on developing the mathematical aspects of his work.

Organocatalyzed C–C Ring Construction: The Bradshaw/Bonjoch Synthesis of (−)-Cermizine B

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
San Antonio ◽  
Bond Formation ◽  
Bryn Mawr ◽  
National Chemical Laboratory ◽  
Chemical Laboratory ◽  
Enantiomerically Pure ◽  
University Of Texas ◽  
National University ◽  
Institute Of Technology ◽  
The University

In a continuation of his studies (OHL20141229, OHL20140811) of organocatalyzed 2+2 photocycloaddition, Thorsten Bach of the Technische Universität München assembled (Angew. Chem. Int. Ed. 2014, 53, 7661) 3 by adding 2 to 1. Li-Xin Wang of the Chengdu Institute of Organic Chemistry also used (Org. Lett. 2014, 16, 6436) an organocatalyst to effect the addition of 5 to 4 to give 6. Shuichi Nakamura of the Nagoya Institute of Technology devised (Org. Lett. 2014, 16, 4452) an organocatalyst that mediated the enantioselective opening of the aziridine 7 to 8. Zhi Li of the National University of Singapore cloned (Chem. Commun. 2014, 50, 9729) an enzyme from Acinetobacter sp. RS1 that reduced 9 to 10. Gregory C. Fu of Caltech developed (Angew. Chem. Int. Ed. 2014, 53, 13183) a phosphine catalyst that directed the addition of 12 to 11 to give 13. Armido Studer of the Westfälische Wilhelms-Universität Münster showed (Angew. Chem. Int. Ed. 2014, 53, 9622) that 15 could be added to 14 to give 16 in high ee. Akkattu T. Biju of CSIR-National Chemical Laboratory described (Chem. Commun. 2014, 50, 14539) related results. The photostimulated enantioselective ketone alkylation developed (Chem. Sci. 2014, 5, 2438) by Paolo Melchiorre of ICIQ was powerful enough to enable the alkyl­ation of 17 with 18 to give 19, overcoming the stereoelectronic preference for axial bond formation. David W. Lupton of Monash University established (J. Am. Chem. Soc. 2014, 136, 14397) the organocatalyzed transformation of the dienyl ester 20 to 21. James McNulty of McMaster University added (Angew. Chem. Int. Ed. 2014, 53, 8450) azido acetone 23 to 22 to give 24 in high ee. There are sixteen enantiomerically-pure diastereomers of the product 27. John C.-G. Zhao of the University of Texas at San Antonio showed (Angew. Chem. Int. Ed. 2014, 53, 7619) that with the proper choice of organocatalyst, with or without subsequent epimerization, it was possible to selectively prepare any one of eight of those diastereomers by the addition of 26 to 25. William P. Malachowski of Bryn Mawr College showed (Tetrahedron Lett. 2014, 55, 4616) that 28, readily prepared by a Birch reduction protocol, was converted by heating followed by exposure to catalytic Me3P to the angularly-substituted octalone 29.

C–O Ring-Containing Natural Products: Cyanolide A (Krische), Bisabosqual A (Parker), Iso-Eriobrucinol A (Hsung), Trichodermatide A (Hiroya), Batrachotoxin Core (Du Bois)

2017 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Radical Cyclization ◽  
Ethyl Vinyl ◽  
University Of Texas ◽  
Iridium Catalysis ◽  
University Of Wisconsin ◽  
Bisabosqual A ◽  
The University ◽  
Very High

Michael J. Krische at the University of Texas at Austin developed (Angew. Chem. Int. Ed. 2013, 52, 4470) a total synthesis of cyanolide A 7 in only seven steps, a sequence so short it is shown here in its entirety. Diol 1 was subjected to enantioselective cat­alytic bisallylation under iridium catalysis to furnish 2 with very high levels of ste­reocontrol. Cross metathesis using ruthenium catalyst 3 first with ethyl vinyl ketone and then with ethylene resulted in the production of pyran 4. Glycosylation of 4 with phenylthioglycoside 5, stereoselective reduction of the ketone function, and oxidative cleavage of the olefin then furnished the carboxylic acid 6. Finally, dimerization of 6 with 2-methyl-6-nitrobenzoic anhydride (MBNA) yielded cyanolide A. Kathlyn A. Parker at Stony Brook University reported (J. Am. Chem. Soc. 2013, 135, 582) a tandem radical cyclization strategy for the total synthesis of bisabosqual A 11. The key substrate 9 was prepared in three steps from the diester 8. Treatment of 9 with tri-s-butylborane and TTMS in the presence of air induced the tandem 5-exo, 6-exo radical cyclization to produce the complete core 10 of the natural product as a mixture of diastereomers, which could be equilibrated. Some further redox maneu­vers then led to bisabosqual A. Richard P. Hsung at the University of Wisconsin, Madison disclosed (Org. Lett. 2013, 15, 3130) a very brief synthesis of iso-eriobrucinol A and related isomers using a unique cascade sequence. First, phloroglucinol 12 and citral 13 were condensed using piperidine and acetic anhydride. The product of this operation was the tetracy­clic cyclobutane 14, the result of an oxa-[3+3] annulation followed by a stepwise, cat­ionic [2+2] cycloaddition. Treatment of 14 with methyl propiolate in the presence of catalytic indium(III) chloride under microwave irradiation furnished iso-eriobrucinol A, as well as the isomeric natural product iso-eriobrucinol B. A concise approach to trichodermatide A 19 was developed (Angew. Chem. Int. Ed. 2013, 52, 3546) by Kou Hiroya at Musashino University. Aldehyde 16, which was syn­thesized from L-tartaric acid, was condensed with 1,3-cyclohexanedione in the presence of piperidine, resulting in diketone 17.

Carbocyclic Construction: The Deng Synthesis of (-)-Plicatic Acid

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Brefeldin A ◽  
Conjugate Addition ◽  
Oxidative Cyclization ◽  
Ring Closure ◽  
Silyl Ether ◽  
University Of Pittsburgh ◽  
University Of Wisconsin ◽  
Institute Of Technology ◽  
The University ◽  
Academy Of Sciences

Tehshik P. Yoon of the University of Wisconsin uncovered (J. Am. Chem. Soc. 2009, 131, 14604) conditions for the crossed photodimerization of acyclic enones. Minoru Isobe of Nagoya University extended (Synlett 2009, 1157) conjugate addition–intramolecular epoxide opening to substrates such as 4, leading to the cyclobutane 6 with high diastereocontrol. In the course of a total synthesis of (+)-brefeldin A, Jinsung Tae of Yonsei University established (Synlett 2009, 1303) conditions for the trans-selective cyclization of 7 to 8. Cyclization with TiCl4 gave the alternative cis diastereomer. Several methods have been put forward for the conversion of carbohydrate derivatives to carbocycles. Yeun-Mi Tsai of the National Taiwan University found (Tetrahedron Lett . 2009, 50, 3805) that acyl silanes such as 9 cyclized efficiently under free radical conditions, leading to the silyl ether 10. Tanmaya Pathak of the Indian Institute of Technology, Kharagpur, developed (Eur. J. Org. Chem. 2009, 872) the tandem conjugate addition– intramolecular alkylation conversion of 11 to 13. Slawomir Jarosz of the Polish Academy of Sciences, Warsawza, observed (Heterocycles 2009, 80, 1303) that the oxime derived from 14 cyclized to 15. The cyclization was accelerated by high pressure. Cyclohexanes can also be prepared from carbohydrates. Tony K. M. Shing of the Chinese University of Hong Kong showed (Organic. Lett. 2009, 11, 5070) that the nitrile oxide derived from 16 cyclized to 17, that he carried on to (-)-gabosine O. John K. Gallos of the Aristotle University of Thessaloniki described (Tetrahedron Lett. 2009, 50, 6916) related work. Paul E. Floreancig of the University of Pittsburgh devised (Organic. Lett. 2009, 11, 3152) conditions for the oxidative cyclization of 18 to 19. Ring closure proceeded with high equatorial selectivity. Kou Hiroya of Tohoku University found (J. Org. Chem. 2009, 74, 6623) that the single oxygenated stereogenic center of 20 directed the dissolving metal reduction–enolate trapping, leading to 21. Similarly, Susumu Kobayashi of the Tokyo University of Science showed (Synlett 2009, 1605) that the oxygenated stereogenic centers of 22 set the alkylated centers of 23. Many marine organisms are able to carry out brominative and chlorinative polyolefin cyclizations.

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