bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional Group Transformations
Authors: Taber Douglass
Published: November 2020

Jeffrey C. Pelletier of Wyeth Research, Collegeville, PA has developed (Tetrahedron Lett. 2007, 48, 7745) a easy work-up Mitsunobu procedure for the conversion of a primary alcohol such as 1 to the corresponding primary amine 2. Shlomo Rozen of Tel-Aviv University has taken advantage (J. Org. Chem. 2007, 72, 6500) of his own method for oxidation of a primary amine to the nitro compound to effect net conversion of an amino ester 3 to the alkylated amino ester 5. Note that the free amine of 3 or 5 would react immediately with methyl iodide. Keith A. Woerpel of the University of California, Irvine has uncovered (J. Am. Chem. Soc. 2007, 129, 12602) a Cu catalyst that, with 7, effected direct conversion of silyl ethers such as 6 to the allyl silane 8. An Ag catalyst gave 9, which also shows arllyl silane reactivity. Biswanath Das of the Indian Institute of Chemical Technology, Hyderabad has established (Tetrahedron Lett. 2007, 48, 6681) a compact procedure for the direct conversion of an aromatic aldehyde such as 10 to the benzylic halide 11. This will be especially useful for directly generating benzylic halides that are particularly reactive. α-Sulfinylation of ketones often requires intial generation of the enolate. J. S. Yadav, also of the Indian Institute of Chemical Technology, Hyderabad, has devised (Tetrahedron Lett. 2007, 48, 5243) an oxidative protocol for installing sulfur adjacent to a ketone. In a related development, Richard S. Grainger of the University of Birmingham has established (Angew. Chem. Int. Ed. 2007, 46, 5377) a simple procedure for the conversion of thio esters such as 14 to the corresponding ketone 16. Yoshiya Fukumoto of Osaka University has shown (J. Am. Chem. Soc. 2007, 129, 13792) that a terminal alkyne 17 can be directly converted into the enamine 18 by Rh-catalyzed addition of a secondary amine. Lukas Hintermann and Carsten Bolm of RWTH Aachen have found (J. Org. Chem. 2007, 72, 5704) that inclusion of water gave the aldehyde, which could be oxidized with the residual Ru catalyst to the acid.
C-C Single Bond Construction
Authors: Taber Douglass
Published: November 2020

Several remarkable one-carbon homologations have recently appeared. André B. Charette of the Université de Montréal reported (J. Org. Chem. 2008, 73, 8097) the alkylation of diiodomethane with alkyl iodides such as 1, to give the diiodoalkane 2. Carlo Punta and the late Ombretta Porta of the Politecnico di Milano effected (Organic Lett. 2008, 10, 5063) reductive condensation of an amine 3 with an aldehyde 4 in the presence of methanol, to give the amino alcohol 5. Timothy S. Snowden of the University of Alabama showed (Organic Lett. 2008, 10, 3853) that NaBH4 reduced the carbinol 7, easily prepared from the aldehyde 6, to the acid 8. Ram N. Ram of the Indian Institute of Technology, Delhi found (J. Org. Chem. 2008, 73, 5633) that CuCl reduced 7 to the chloro ketone 9. Kálmán J. Szabó of Stockholm University extended (Chem. Commun. 2008, 3420) his elegant work on in situ borinate formation, coupling, in one pot, the allylic alcohol 10 with the acetal 11 (hydrolysed in situ) to deliver the alcohol 12 as a single diastereomer. Samir Z. Zard of the Ecole Polytechnique developed (J. Am. Chem. Soc. 2008, 130, 8898) the 6-fluoropyridyloxy ether of 13 as an effective radical leaving group, enabling efficient coupling with 14, activated by dilauroyl peroxide, to give 15. Shu Kobayashi of the University of Tokyo established (Chem. Commun. 2008, 6354) that the anion of the sulfonyl imidate 17 participated in direct Pd-mediated allylic coupling with the carbonate 16. The product sulfonyl imidate 18 is itself of medicinal interest. It is also easily converted to other functional groups, including the aldehyde 19. Jianliang Xiao of the University of Liverpool found (J. Am. Chem. Soc. 2008, 130, 10510) that Pd-mediated coupling of an aldehyde 21 in the presence of pyrrolidine led to the ketone 22. The reaction is probably proceeding via Heck coupling of the aryl halide with the in situ generated enamine. Alois Fürstner of the Max Planck Institut, Mülheim observed (J. Am. Chem. Soc. 2008, 130, 8773) that in the presence of the simple catalyst Fe(acac)3 a Grignard reagent 24 coupled smoothly with an aryl halide 23 to give 25.
Total Synthesis by Alkene Metathesis: Amphidinolide X (Urpí/Vilarrasa), Dactylolide (Jennings), Cytotrienin A (Hayashi), Lepadin B (Charette), Blumiolide C (Altmann)
Authors: Taber Douglass
Published: November 2020

To assemble the framework of the cytotoxic macrolide Amphidinolide X 3, Fèlix Urpí and Jaume Vilarrasa of the Universitat de Barcelona devised (Organic Lett. 2008, 10, 5191) the ring-closing metathesis of the alkenyl silane 1. No Ru catalyst was effective, but the Schrock Mo catalyst worked well. In the course of a synthesis of (-)-Dactylolide 6, Michael P. Jennings of the University of Alabama offered (J. Org. Chem. 2008, 73, 5965) a timely reminder of the particular reactivity of allylic alcohols in ring-closing metathesis. The cyclization of 4 to 5 proceeded smoothly, but attempted ring closing of the corresponding bis silyl ether failed. Polyenes such as ( + )-Cytotrienin A 8 are notoriously unstable. It is remarkable that Yujiro Hayashi of the Tokyo University of Science could (Angew. Chem. Int. Ed. 2008, 47, 6657) assemble the triene of 8 by the ring-closing metathesis of the highly functionalized precursor 7. Bicyclo [2.2.2] structures such as 9 are readily available by the addition of, in this case, methyl acrylate to an enantiomerically-pure 2-methylated dihydropyridine. André B. Charette of the Université de Montréal found (J. Am. Chem. Soc. 2008, 130, 13873) that 9 responded well to ring-opening/ring-closing metathesis, to give the octahydroquinoline 10. Functional group manipulation converted 10 into the Clavelina alkaloid ( + )-Lepadin B 11. The construction of trisubstituted alkenes by ring-closing metathesis can be difficult, and medium rings with their transannular strain are notoriously challenging to form. Nevertheless, Karl-Heinz Altmann of the ETH Zürich was able (Angew. Chem. Int. Ed. 2008, 47, 10081), using the H2 catalyst, to cyclize 12 to cyclononene 13, the precursor to the Xenia lactone ( + )-Blumiolide C 14. It is noteworthy that these fi ve syntheses used four different metathesis catalysts in the key alkene forming step. For the cyclization of 7, the use of the Grubbs first generation catalyst G1, that couples terminal alkenes but tends not to interact with internal alkenes, was probably critical to success.
Enantioselective Synthesis of Alcohols and Amines
Authors: Taber Douglass
Published: November 2020

Enantiomerically-enriched alkoxy stannanes such as 3 are versatile intermediates for synthesis. John R. Falck of UT Southwestern found (Angew. Chem. Int. Ed. 2008, 47, 6586) that the simple combination of Bu3 SnH and Et2Zn generated a reagent that added to aldehydes such as 1 under catalysis by the MIB amino alcohol introduced by Nugent (Chem. Commun. 1999, 1369) to give the adduct 3 in high ee. Gonzalo Blay and José R. Pedro of the Universitat de València showed (Chem. Commun. 2008, 4840) that it was possible to modulate the reactivity of the acidic 4, allowing catalyzed formation of the high ee adduct 5 to dominate. Xiaoming Feng of Sichuan University developed (J. Am. Chem. Soc. 2008, 130, 15770) a Ni catalyst for the intermolecular ene reaction of 6 with 7 to give 8 in high ee. Enantioselective allylation is a key transformation in current organic synthesis. Yoshito Kishi of Harvard University optimized (Organic Lett. 2008, 10, 3073) enantioselective Cr-mediated allylation, with a ligand that can be easily recovered and recycled. Michael J. Krische of UT Austin devised (J. Am. Chem. Soc. 2008, 130, 14891) a ligand-catalyst combination for effecting the enantioselective allylation of alcohols such as 12 . Brian M. Stoltz of Caltech developed (Angew. Chem. Int. Ed. 2008, 47, 6873) a protocol for the enantioselective allylation of the enol ether 15, leading to the construction of oxygenated quaternary centers. Adducts such as 11 and 17 are of interest, inter alia , as direct precursors, by elimination, of the corresponding alkynes. Simon Blakey of Emory University designed (Angew. Chem. Int. Ed. 2008, 47, 6825) a Ru catalyst that mediated enantioselective intramolecular C-H amination, converting the simple alcohol derivative 18 into the versatile secondary amine 19 in high ee. We established (J. Org. Chem. 2008, 73, 9334) a procedure, based on diazo transfer followed by Rh-mediated intermolecular N-H insertion, for aminating menthyl esters and separating the product diastereomers. The menthyl group, easily removed (TFA) from 21, served as a useful reporter of ee, by 1H NMR of the upfield methyl doublets. Wolfgang Kroutil of the University of Graz found (Adv. Synth. Cat. 2008, 350, 2761) that ω-transaminases could effect the reductive amination of methyl ketones such as 22 in high ee.
Stereocontrolled Construction of Arrays of Stereogenic Centers
Authors: Taber Douglass
Published: November 2020

The Sharpless osmium-catalyzed asymmetric dihydroxylation is widely used. Lawrence Que, Jr. of the University of Minnesota designed (Angew. Chem. Int. Ed. 2008, 47, 1887) a catalyst with the inexpensive Fe that appears to be at least as effective, converting 1 to 2 in high ee. In an alternative approach, Bernd Plietker of the Universität Stuttgart used (J. Org. Chem. 2008, 73, 3218) chiral auxiliary control to direct dihydroxylation. The diastereomers of 4 were readily differentiated. Defined arrays of stereogenic centers can also be constructed by homologation. Armando Córdova of Stockholm University condensed (Tetrahedron Lett. 2008, 49, 803) dihydroxy acetone 6 with an in situ generated imine 5 to give the amino diol 8. In parallel work, Carlos F. Barbas III of Scripps/La Jolla described (Organic Lett. 2008, 10, 1621) a related addition to aldehydes. Magnus Rueping of University Frankfurt found (Organic Lett. 2008, 10, 1731) conditions for the addition of a nitro alkane such as 9 to the imine 10 to give 11. Keiji Maruoka of Kyoto University devised (J. Am. Chem. Soc. 2008, 130, 3728) a chiral amine that mediated the enantioselective iodination of aldehydes such as 12. Direct cyanohydrin formation delivered 13 in high de and ee. The epoxide 14 is readily prepared in high ee from crotyl alcohol. Barry M. Trost of Stanford University found (Organic Lett. 2008, 10, 1893) that 14 could be opened with 15, to give 16 with high regio- and diastereocontrol. Jérôme Blanchet of the Université de Caen Basse-Normandie optimized (Organic Lett. 2008, 10 , 1029) the amine 19 as a catalyst for the condensation of ketones such as 17 with the imine 18, to give 20. Michael J. Krische of the University of Texas has explored (J. Am. Chem. Soc. 2008, 130, 2746) the in situ generation of chiral Rh enolates from enones such as 21, and the subsequent aldol condensation with aldehydes such as 22. Shu Kobayashi of the University of Tokyo found (Organic Lett. 2008, 10, 807) that the conjugate addition of 25 to 24 mediated by a chiral Ca catalyst proceeded with high enantiocontrol at both of the newly formed stereogenic centers, to give 26.
Stereoselective C-N Ring Construction
Authors: Taber Douglass
Published: November 2020

Ryoichi Kuwano of Kyushu University showed (J. Am. Chem. Soc. 2008, 130, 808) that diastereomerically and enantiomerically pure pyrollidines such as 2 could be prepared by hydrogenation of the corresponding pyrrole. Victor S. Martín of Universidad de la Laguna found (Organic Lett. 2008, 10, 2349) that the stereochemical outcome of the pyrrolidine-forming Nicholas cyclization could be directed by the protecting group on the N. Jianbo Wang of Peking University established (J. Org. Chem. 2008, 73, 1971) a convenient route to diazo esters such as 6. N-H insertion led to the pyrrolidine, which Zhen-Jiang Xu of the Shanghai Institute of Organic Chemistry and Chi-Ming Che of the University of Hong Kong showed (Organic Lett. 2008, 10, 1529) could be reduced with high diastereoselectivity to the hydroxy ester 7. Alternatively, Professor Wang found that photochemical Wolff rearrangement of 6 delivered the pyrrolidone 8 . Martin J. Slater and Shiping Xie of GlaxoSmithKline optimized (J. Org. Chem. 2008, 73, 3094) the hydroquinine catalyzed enantioselective 3+2 cycloaddition of 9 and 10, leading to the pyrrolidine 11 with high diastereocontrol. Shu Kobayashi of the University of Tokyo developed (Adv. Synth. Cat. 2008, 350, 647) a practical protocol for the aza Diels-Alder construction of enantiomerically-pure piperidines such as 14 . Biao Yu of the Shanghai Institute of Organic Chemistry cyclized (Tetrahedron Lett. 2008, 49, 672) the product from the proline-catalyzed enantioselective aldol of 15 and 16, leading to the substituted piperidine 17 . Michael Shipman of the University of Warwick described (Tetrahedron Lett. 2008, 49, 250) the cyclization of the aziridine derived from 18, that proceeded to give 19 as a single diastereomer, apparently via kinetic side-chain protonation. Takeo Kawabata of Kyoto University found (J. Am. Chem. Soc. 2008, 130, 4153) that intramolecular alkylation to form four, five and six-membered rings from amino esters such as 21 proceeded with remarkable enantioretention. Géraldine Masson and Jieping Zhu of CNRS, Gif-sur-Yvette, condensed (Organic Lett. 2008, 10, 1509) cinnamaldehyde 23 with cyanide and an ω-alkenyl amine to give the intramolecular aza-Diels-Alder substrate 24. Hongbin Zhai of the Shanghai Institute of Organic Chemistry acylated (J. Org. Chem. 2008, 73, 3589) 26 with 27, leading to the ring-closing metathesis precursor 28.
Alkaloid Synthesis: Crispine A (Zhou), Cermizine C (Zhang), Tangutorine (Poupon), FR901483 (Kerr), Serratezomine A (Johnston)
Authors: Taber Douglass
Published: November 2020

Enantioselective hydrogenation of enamides is a well-established transformation. The corresponding reduction of enamines has been elusive. Qi-Lin Zhou of Nankai University designed (J. Am. Chem. Soc. 2009, 131, 1366) an Ir catalyst that reduced 2 to the Carpus alkaloid Crispine A 3 in high ee. Direct conversion of C-H to C-C bonds is a powerful synthetic transformation. Liming Zhang, now at the University of California, Santa Barbara, observed (J. Am. Chem. Soc. 2009, 131, 8394) that a gold catalyst converted the N-oxide of 4 into 5, that was then deoxygenated to give Cermizine C 6. The gold catalyst and the N-oxide combined to convert the alkyne into an α-keto carbene, in the process reducing the N-oxide back to the amine. The carbene then abstracted a hydride from the carbon adjacent to the amine, generating an intermediate that collapsed to give 5 with high diastereocontrol. Tangutorine 10, isolated from the leaves of Nitraria tangutorum, affects the morphology of human colon cancer cells. In a biomimetic approach, Erwan Poupon of the Université Paris-Sud stirred (Organic Lett . 2009, 11, 1891) glutaraldehyde 7 with bicarbonate to give an unstable carbocyclic dimer. Addition of tryptamine in acetic acid delivered the pentacyclic product 9, that was reduced with borohydride to give the crystalline Tangutorine 10. FR901483, a potent immunosuppressive isolated from a Cladobotyrum fermentation broth, presents an challenging array of stereogenic centers in its tricyclic skeleton. Michael A. Kerr of the University of Western Ontario prepared (Organic Lett. 2009, 11, 777) the activated cyclopropane 11, then effected intramolecular dipolar opening with an intermediate imine, yielding the tricyclic 12. The Lycopodium alkaloid Serratezomine A 21 presents a similarly challenging array of stereogenic centers in its tetracyclic structure. Jeffrey N. Johnston of Vanderbilt University constructed (J. Am. Chem. Soc. 2009, 131, 3470) the pyrrolidine ring of 15 using the imine free radical acceptor that he had previously developed. Having the alkene-Sn bond in place then enabled coupling with the acid chloride 16. Oxidative deprotection of 17 freed the enamine, that added in a conjugate sense to the unsaturated ester, kinetically setting the axial branch of 18.
Organocatalytic C-C Ring Construction: (+)-Ricciocarpin A (List) and (-)-Aromadendranediol (MacMillan)
Authors: Taber Douglass
Published: November 2020

Yoshiji Takemoto of Kyoto University designed (Organic Lett. 2009, 11, 2425) an organocatalyst for the enantioselective conjugate addition of alkene boronic acids to γ-hydroxy enones, leading to 1 in high ee. Attempted Mitsunobu coupling led to the cyclopropane 2, while bromoetherification followed by intramolecular alkylation delivered the cyclopropane 3. Jeffrey W. Bode of the University of Pennsylvania demonstrated (Organic Lett. 2009, 11, 677) a remarkable dichotomy in the reactivity of N-heterocyclic carbenes. A triazolium precatalyst combined 4 and 5 to give 6, whereas an imidazolium precatalyst combined 4 and 5 to give 7. Xinmiao Liang of the Dalian Institute of Chemical Physics and Jinxing Ye of the East China University of Science and Technology devised (Organic Lett. 2009, 11, 753) a Cinchona -derived catalyst that converted the prochiral cyclohexenone 8 into the diester 10 in high ee. Rich G. Carter of Oregon State University found (J. Org. Chem. 2009, 74, 2246) a simple sulfonamide-based proline catalyst that effected the Mannich condensation of the prochiral ketone with ethyl glyoxalate 12 and the amine 13, leading to the amine 14. In the first pot of a concise, three-pot synthesis of (-)-oseltamivir, Yujiro Hayashi of the Tokyo University of Science combined (Angew. Chem. Int. Ed. 2009, 48, 1304) 15 and 16 in the presence of a catalytic amount of diphenyl prolinol TMS ether to give an intermediate nitro aldehyde. Addition of the phosphonate 17 led to a cyclohexenecarboxylate, that on the addition of the thiophenol 18 equilibrated to the ester 19. Ying-Chun Chen of Sichuan University used (Organic Lett. 2009, 11, 2848) a related diaryl prolinol TMS ether to direct the condensation of the readily-prepared phosphorane 20 with the unsaturated aldehyde 21 to give the cyclohexenone 22. Armando Córdova of Stockholm University also used (Tetrahedron Lett. 2009, 50, 3458) diphenyl prolinol TMS ether to mediate the addition of 24 to 23. The subsequent intramolecular aldol condensation proceeded with high diastereocontrol, leading to 25. Benjamin List of the Max-Planck Institut, Mülheim employed (Nat. Chem. 2009, 1, 225) a MacMillan catalyst for the reductive cyclization of 26.
Transition Metal-Mediated Construction of Carbocycles: Dimethyl Gloiosiphone A (Takahashi), Pasteurestin A (Mulzer), and Pentalenene (Fox)
Authors: Taber Douglass
Published: November 2020

There continue to be new developments in transition metal- and lanthanide-mediated construction of carbocycles. Although a great deal has been published on the asymmetric cyclopropanation of styrene, relatively little had been reported for other classes of alkenes. Tae-Jeong Kim of Kyungpook National University has devised (Tetrahedron Lett. 2007, 48, 8014) a Ru catalyst for the cyclopropanation of simple α-olefins such as 1. X. Peter Zhang of the University of South Florida has developed (J. Am.Chem. Soc. 2007, 129, 12074) a Co catalyst for the cyclopropanation of alkenes such as 5 having electron-withdrawing groups. Alexandre Alexakis of the Université de Genève has reported(Angew. Chem. Int. Ed. 2007, 46, 7462) simple monophosphine ligands that enabled enantioselective conjugate addition to prochiral enones, even difficult substrates such as 8. Seunghoon Shin of Hanyang University has found (Organic Lett. 2007, 9, 3539) an Au catalyst that effected the diastereoselective cyclization of 10 to the cyclohexene 11, and Radomir N. Saicic of the University of Belgrade has carried out (Organic Lett. 2007, 9, 5063), via transient enamine formation, the diastereoselective cyclization of 12 to the cyclohexane 13. Alois Fürstner of the Max-Planck- Institut, Mülheim has devised (J. Am. Chem. Soc. 2007, 129, 14836) a Rh catalyst that cyclized the aldehyde 14 to the cycloheptenone 15. Some of the most exciting investigations reported in recent months have been directed toward the direct diastereo- and enantioselective preparation of polycarbocyclic products. Rai-Shung Liu of National Tsing-Hua University has extended (J. Org. Chem. 2007, 72, 567) the intramolecular Pauson-Khand cyclization to the epoxy enyne 16, leading to the 5-5 product 17. Michel R. Gagné of the University of North Carolina has devised (J. Am. Chem. Soc. 2007, 129, 11880) a Pt catalyst that smoothly cyclized the polyene 18 to the 6-6 product 19. Yoshihiro Sato of Hokkaido University and Miwako Mori of the Health Science University of Hokkaido have described (J. Am. Chem. Soc. 2007, 129, 7730) a Ru catalyst for the cyclization of 20 to the 5-6-5 product 21. Each of these processes proceeded with high diastereocontrol.
The Carter Synthesis of (-)-Lycopodine
Authors: Taber Douglass
Published: November 2020

Rich G. Carter of Oregon State University described (J. Am. Chem. Soc. 2008, 130, 9238) the first enantioselective synthesis of the Lycopodium alkaloid (-)-lyopodine 3. A key step in the assembly of 3 was the diastereoselective intramolecular Michael addition of the keto sulfone of 1 to the enone, leading to the cyclohexanone 2. The key cyclization substrate 1 bore a single secondary methyl group. While that could have been derived from a natural product, it was operationally easier to effect chiral auxiliary controlled conjugate addition to the crotonyl amide 4, leading, after methoxide exchange, to the ester 5. The authors reported that double deprotonation with LiTMP gave superior results, vs. LDA or BuLi, in the condensation of 6 with 5 to give 7. Metathesis with pentenone 8 gave the intramolecular Michael substrate 1. The authors thought that they would need a chiral catalyst to drive the desired stereocontrol in the cyclization of 1 to 2. As a control, they tried an achiral base first, and were pleased to observe the desired diastereomer crystallize from the reaction mixture in 89% yield. The structure of 2 was confirmed by X-ray crystallography. To prepare for the intramolecular Mannich condensation, the azide was reduced to give the imine, and the methyl ketone was converted to the silyl enol ether. Under Lewis acid conditions, the sulfonyl group underwent an unanticipated 1,3-migration, to give 11. Cyclization of 12 then delivered the crystalline 14. Reduction converted 14 to the known (in racemic form) ketone 15. To complete the synthesis, the amine 15 was alkylated with 16 to give the alcohol 17. Oppenauer oxidation followed by aldol condensation delivered the cyclized enone, that was reduced with the Stryker reagent to give (-)-Lycopodine 3. Both the cyclization of 1 to 2 and the cyclization of 9 to 14 are striking. It may be that the steric demand of the phenylsulfonyl group destabilizes the competing transition state for the cyclization of 1.
Mechanisms of Atmospheric Oxidation of the Oxygenates
Authors: Calvert Jack , Mellouki Abdelwahid , Orlando John , Pilling Michael , Wallington Timothy
Published: November 2020

Prepared by an international team of eminent atmospheric scientists, Mechanisms of Atmospheric Oxidation of the Oxygenates is an authoritative source of information on the role of oxygenates in the chemistry of the atmosphere. The oxygenates, including the many different alcohols, ethers, aldehydes, ketones, acids, esters, and nitrogen-atom containing oxygenates, are of special interest today due to their increased use as alternative fuels and fuel additives. This book describes the physical properties of oxygenates, as well as the chemical and photochemical parameters that determine their reaction pathways in the atmosphere. Quantitative descriptions of the pathways of the oxygenates from release or formation in the atmosphere to final products are provided, as is a comprehensive review and evaluation of the extensive kinetic literature on the atmospheric chemistry of the different oxygenates and their many halogen-atom substituted analogues. This book will be of interest to modelers of atmospheric chemistry, environmental scientists and engineers, and air quality planning agencies as a useful input for development of realistic modules designed to simulate the atmospheric chemistry of the oxygenates, their major oxidation products, and their influence on ozone and other trace gases within the troposhere.
Rate Coefficients and Mechanisms for the Atmospheric Oxidation of the Alcohols
Authors: Calvert Jack , Mellouki Abdelwahid , Orlando John , Pilling Michael , Wallington Timothy
Published: November 2020

The presence of alcohols in the atmosphere is attributable to natural and anthropogenic sources (e.g., Graedel, 1978). They are released into the atmosphere as a result of their use as fuels (e.g., methanol, ethanol), fuel additives (e.g., ethanol), solvents (e.g., ethanol, propanol) and as starting materials or intermediates for organic synthesis in a large number of industries (e.g., isobutanol, isopentanol, hexylene glycol). Vegetation also provides a significant source of alcohols to the atmosphere (Kesselmeier and Straudt, 1999; Fall, 2003). A number of saturated and unsaturated alcohols have been identified to be biogenically emitted (e.g., methanol, ethanol, methylbutenol, linalool, Z-hex-3-en-1-ol “leaf alcohol”). High ambient concentrations of certain alcohols have been measured in some areas, up to 68 ppb for ethanol in Porto Alegre, Brazil (Grosjean et al., 1998a) and up to 3 ppb for 2-methyl-3-buten-2-ol in the Colorado mountains (Goldan et al., 1993). Amore complete description of the emission sources and ambient concentrations of alcohols is given in chapter I. Reaction with OH radicals is the dominant atmospheric loss process for the saturated alcohols while reactions with NO3, O3, and photolysis are negligible.
Rate Coefficients and Mechanisms for the Atmospheric Oxidation of the N-Atom-Containing Oxygenates
Authors: Calvert Jack , Mellouki Abdelwahid , Orlando John , Pilling Michael , Wallington Timothy
Published: November 2020

The many different nitrogen-containing oxygenated volatile organic compounds that are present in the troposphere play important roles in the chemistry of our atmosphere. They can be emitted directly into the atmosphere, such as in the case of amides that are widely used as organic solvents, starting materials, or intermediates in different industries (e.g., synthetic polymers, manufacture of dyes, and synthesis of pesticides). Amides are formed in situ as intermediate products in the degradation of amines (e.g., see Tuazon et al., 1994; Finlayson-Pitts and Pitts, 2000). Nitrogen-containing oxygenated organic compounds are formed in the atmosphere also via reactions of alkoxy (RO) and alkyl peroxy radicals (RO2) with NO or NO2 leading to alkyl nitrates, alkyl nitrites, and peroxy acetyl nitrates. However, primary sources of these organic species have also been suggested such as diesel and other engines and biomass burning (e.g., see Simpson et al., 2002). Alkyl nitrates (RONO2) have been detected in both the urban and the remote troposphere (e.g., see Roberts, 1990; Walega et al., 1992; Atlas et al., 1992; Ridley et al., 1997; and Stroud et al., 2001; see also section I-D). Nitrates are formed as minor products in the reaction of peroxy radicals with NO. The nitrate yield increases with the size of peroxy radicals and can be as high as 20–30% for large (>C6) radicals (Calvert et al., 2008). Peroxyacyl nitrates (RC(O)O2NO2) are important constituents of urban air pollution. They have been identified in ambient air (e.g., see Bertman and Roberts, 1991; Williams et al., 1997, 2000; Nouaime et al., 1998; Hansel and Wisthaler, 2000; also see section I-D). They are formed from photochemical reactions via RC(O)O2 + NO2. A major role of these compounds is their capacity to act as a reservoir for NOx that can be transported from polluted urban to remote regions that are poor NOx regions and where their presence can increase NOx levels (Roberts, 1990). As with other volatile organic compounds (VOCs), once released to the atmosphere, nitrogen-containing organic compounds are expected to undergo degradation primarily via reaction with hydroxyl and nitrate radicals, reaction with ozone, and photolysis. Thermal decomposition is an important loss process for the peroxyacyl nitrates.
Audio Buffers
Authors: Manzo V. J
Published: November 2020

In the last chapter, we discussed ways to play back prerecorded audio as well as ways to record audio. In this chapter, we will discuss how to record audio into a storage container called a buffer. When we record audio into a buffer, we can manipulate it in various ways in real time. By the end of this chapter, you will be able to record a performance through your microphone and loop the recording while you make sonic changes to it somewhat like the “MIDI Looper” we made in Chapter 10. You will also learn how to make a polyphonic synthesizer that uses a single recording of your voice as the pitches. Buffers are storage containers for audio. Once audio is contained inside a buffer, the audio can be played back at a variable speed, looped, reversed, and have other types of manipulations performed on it. Buffers are great for “live looping” in which performers may record a musical idea into a buffer and then have the idea play repeatedly as they improvise or perform a second line on top of it. This technique is similar in function to the “MIDI looper” we made in Chapter 10 but uses actual audio instead of MIDI. Users may also decide to change aspects of the “looped” audio in the ways mentioned above while they are performing. We will begin our exploration of buffers by loading a prerecorded audio file into a buffer. Later on, we will allow our buffer to hold audio we record in real time. To implement a buffer in Max, we need the buffer~ object. We will give the buffer~ object a name as its argument to distinguish it from other buffer~ objects. Like other objects that take names as their argument such as coll and table, naming the buffer~ allows other MSP objects with the same name argument to work with the same audio inside of the buffer.
Mogollon Plateau: Fires Present and Future
Authors: deBuys William
Published: November 2020

Early on June 19, 2002, Paul Garcia looked off the rim of the Mogollon Plateau and did not like what he saw. Down toward Cibecue, the capital of the Fort Apache Reservation, home of the White Mountain Apaches, dark smoke boiled into the Arizona sky. The wind was pushing it in Garcia’s direction, toward the rim, as the prevailing southwest wind always pushed fires that start down on the Rez. The churning smoke—dark-tinged because of solid materials that volatilized without burning—told Garcia that the fire was gaining energy, building strength. He was the fire management officer of the Lakeside Ranger District, a unit of the Sitgreaves National Forest. His boss, a couple of steps up the chain of command, was Forest Supervisor John Bedell, who remembers getting a call from Garcia: “He said, ‘You know, this thing has some potential. . . . If they don’t catch it today, it’s going to get pretty big.’ ” The firefighters on the reservation didn’t catch it. The Rodeo Fire, which began as an act of arson near the Cibecue rodeo grounds, grew from a size of 1,000 acres on June 18 to 55,000 acres the next day. Garcia, Bedell, and a burgeoning army of Forest Service firefighters scrambled to meet the fire atop the rim, hoping to hold it at the rim road that marked the boundary between the reservation and the National Forest. They did not succeed. By mid-afternoon the fire had developed multiple towering plumes of smoke and ash. Its front advanced at an average rate of four miles an hour. Whole stands of eighty-foot trees ignited in an instant, shooting flames 400 feet high and lofting aerial firebrands half a mile downwind. By 4:00 p.m., some of those firebrands were spotting across the rim road. The Mogollon Rim is one of the most pronounced topographic features of the Southwest.
What Administrators Do
Authors: Ginsberg Benjamin
Published: November 2020

The Number of administrators and staffers on university campuses has increased so rapidly in recent years that often there is simply not enough work to keep all of them busy. I have spent time in university administrative suites and in the corridors of public agencies. In both settings I am always struck by the fact that so many well-paid individuals have so little to do. To fill their time, administrators engage in a number of make-work activities. They attend meetings and conferences, they organize and attend administrative and staff retreats, and they participate in the strategic planning processes that have become commonplace on many campuses. While these activities are time consuming, their actual contribution to the core research and teaching missions of the university is questionable. Little would be lost if all pending administrative retreats and conferences, as well as four of every five staff meetings (these could be selected at random), were canceled tomorrow. And, as to the ubiquitous campus planning exercises, as we shall see below, the planning process functions mainly to enhance the power of senior managers. The actual plans produced after the investment of thousands of hours of staff time are usually filed away and quickly forgotten. There is, to be sure, one realm in which administrators as-a-class have proven extraordinarily adept. This is the general domain of fund-raising. College and university administrators have built a massive fund-raising apparatus that, every year, collects hundreds of millions of dollars in gifts and bequests mainly, though not exclusively, from alumni whose sense of nostalgia or obligation make them easy marks for fund-raisers’ finely-honed tactics. Even during the depths of the recession in 2009, schools were able to raise money. On the one hand, the donors who give selflessly to their schools deserve to be commended for their beneficence. At the same time, it should still be noted that, as is so often the case in the not-for-profit world, university administrators appropriate much of this money to support—what else?— more administration.
Managerial Pathologies
Authors: Ginsberg Benjamin
Published: November 2020

When they are not meeting, retreating, fund-raising, and planning, administrators claim to be managing the fiscal and other operational business of the university. And to bolster their claims of specialized managerial competence, an increasing number of university administrators have gone so far as to add MBA degrees to their dossiers. Some have actually attended business school, while others, as you may recall from chapter 1, simply added MBA degrees to their dossiers. In point of fact, whether or not they hold MBAs, many deanlets’ managerial savvy consists mainly of having the capacity to spout last year’s management buzz words during meetings, retreats, and planning exercises. I often ask for clarifications when I hear a deanlet using such acronyms as SWOT, ECM, TQM, or MBO, the term “benchmarking,” or the ubiquitous “best practices.” Of course, ambitious administrators hope that by demonstrating their familiarity with the latest managerial fads and buzz words they will persuade recruiters and search committees from other universities that they are just the sort of “visionary” academic leaders those schools need. Since the corporate headhunters that control the recruitment of senior administrators generally know next to nothing about academic life and little about the universities they nominally represent, this strategy is often successful. And, why not? In the all administrative university it is entirely appropriate that mastery of managerial psychobabble should pass for academic vision. There are many reasons why the affairs of the university should not be controlled by members of the administrative stratum. Some of these reasons are academic, that is, related to the substance of the university’s core teaching and research missions. We shall turn to these in the next chapter. The other reasons to be concerned about the growing power of administrators and managers within the university are essentially managerial. The university’s organizational and institutional interests are not well served by the expanded role of its management cadre. Indeed, the growing power of management and the decline of the faculty’s role in governance has exposed the university to such classic bureaucratic pathologies as shirking, squandering, and stealing.
There Is No Such Thing as Academic Freedom (For Professors): The Rise and Fall of the Tenure System
Authors: Ginsberg Benjamin
Published: November 2020

Many Academics Who are troubled by the growing power of administrators on their campuses believe that their jobs are protected by tenure and their campus activities by academic freedom. Hence, they believe that they, personally, have little to fear from the advent of the all-administrative university. Yet, these unworried professors might do well to fret just a bit. Tenure does not provide absolute protection, and at any rate only about 30 percent of the current professorate is tenured or even on the tenure track. The remaining 70 percent are hired on a contingent basis and can be dismissed at any time. The question of academic freedom is more complex and more dispiriting. In recent years, the federal courts have decided that deanlets, not professors, are entitled to academic freedom. This proposition may be surprising to academics, who, usually without giving the matter much thought, believe they possess a special freedom derived from the German concept of Lehrfreiheit, which they think protects their freedom to teach, to express opinions, and to engage in scholarly inquiry without interference from university administrators or government officials. It certainly seems reasonable to think that professors should possess Lehrfreiheit. Academics play an important part in the production, dissemination, and evaluation of ideas, and a free and dynamic society depends on a steady flow of new ideas in the sciences, politics, and the arts. The late Chief Justice Earl Warren once opined that American society would “stagnate and die” if scholars were not free to inquire, study, and evaluate. Accordingly, he said, academic freedom “is of transcendent value to all of us and not merely to the teachers concerned.” Despite Chief Justice Warren’s endorsement, professors’ ideas and utterances do not have any special constitutional status. Like other Americans, professors have free speech rights under the First Amendment. In a number of cases decided during the 1950s and 1960s, the Supreme Court made it clear that the First Amendment offered professors considerable protection from the efforts of federal, state, and local governments to intrude on their freedom of speech and association.
Notation and Representation: How We Get ’Em to Crack the Code
Authors: Greher Gena R. , Heines Jesse M.
Published: November 2020

Music can and does exist without notation. In fact, its existence predates what we have come to accept as traditional music notation. Many musical traditions have thrived for centuries without any kind of formal codified symbol system to make musical replication easier. Music has existed, and often still exists, as an aurally transmitted art form. The same can’t be said for computers. Though the tongue-in-cheek Hart and Lieberman quote at the beginning of the chapter gets to the heart of the aural and intuitive nature of music’s origins, computer code relies on complex mathematics built, amazingly, on the seemingly simple 1s and 0s of binary arithmetic. Yet just as with music, there are tools and applications that your students can use to express themselves without even thinking about the underlying mathematics. For many of your students, the act of creating, whether it’s making music or developing web content, is accomplished intuitively, without formal training and knowledge of the “tools of the trade”: musical notation and computer code. Sherry Turkle asserts that “today’s children are growing up in the computer culture; all the rest of us are at best its naturalized citizens”. Following that line of reasoning a bit further, let’s assume for a moment that for your students music and computers are ingrained components of their culture. As is sometimes the case, however, the formal acquisition of these tools can often serve as a barrier to further understanding rather than the gateway this knowledge is meant to serve: impeding rather than enabling the creative process. Gardner feels that formal musical training can “be the beginning of the end of most children’s musical development” (p. 38). He believes “the challenge of musical education is to respect and build upon the young child’s own skills and understanding of music rather than impose a curriculum designed largely for adults” (p. 38). Bamberger’s research with college students suggests that students of any age possess musical instincts that, in the proper environment, can be developed and nurtured.
Platforms and Tools: Anything You Can Do, I Need to Do Cheaper
Authors: Greher Gena R. , Heines Jesse M.
Published: November 2020

On their page intended to woo prospective graduate students, the Georgia Tech School of Music website says: . . . Successful design and development of music technology systems must be supported by knowledge of music theory, perception, composition, and performance, as well as digital media, computing, electrical and mechanical engineering, and design. . . . We don’t disagree, but that’s an awful lot to know! What’s more, requiring students to have even a subset of these skills before they can “get in the game” deprives a huge percentage of them the opportunity to learn valuable computing skills through the engaging power of music. There is no end to the money you can spend on technology to gain the ability to design and create. For certain types of projects, professional or “prosumer” software applications boasting the latest bells and whistles might in fact make total economic sense in terms of functionality and time. However, we don’t feel that it’s necessary to jump into the higher end of the market at the beginning stages of learning computational skills. In addition, such costs are prohibitive for most undergraduates and even graduate students. Of course, you could outfit a computer lab available to students with this level of software, but then they would have to do all their assignments in the lab. This is not a practical solution for our students because so many of them are commuters or work off campus and are unable to spend significant time in our labs outside of class time. We think it’s important that students can run the same software on their own systems that is demonstrated in class and with which they are expected to do their assignments. We therefore suggest that you adopt software platforms that you can download freely from the web, but that still allow you to explore broad computing and music concepts common to the higher end platforms. We don’t contend that such software is as sophisticated or as polished as its professional or “prosumer” cousins, but it is most likely fully sufficient for your teaching purposes.
Assessment: Making the Grade
Authors: Greher Gena R. , Heines Jesse M.
Published: November 2020

All students know that different professors grade differently. We’d be willing to bet that your experiences in this area mirror ours, and that you’d agree that the differences go much deeper than we could have imagined. It’s not just a question of one professor being a tough grader while the other is easy, or one grading on established intervals (93–100 = A, 90–92 = A–, 87–89 = B–, 83– 86 = B, etc.) while the other grades “on the curve.” It’s more a question of style: how much feedback students receive on their work and in what form, how the various components in any individual assignment are evaluated to make up an overall grade for that assignment, and how final grades are computed, especially if the computing involves grades of differing weights. There also appear to be quite different “cultures” concerning grades in the sciences and the arts. While students in all disciplines are understandably concerned about their grades—if for no other reason than to maintain the grade point average (GPA) required to keep their financial aid or to avoid a clash with parents—those in the sciences seem to desire more precise accounting than those in the arts. Add to these factors that students in an interdisciplinary course are, by definition, constantly being put into situations outside their comfort zone, and it’s easy to see that the wave of students complaining about grading can be a tsunami waiting to happen. One can discuss grading philosophies forever, but we begin from the premise that if students put reasonable amounts of effort into the coursework, they should get “paid” with a decent grade, which we consider to be B– or better. In fact, one of us believes that all students walk in with an A and it’s the student’s responsibility to maintain that grade. This is especially true in an experimental course such as our Sound Thinking, where we know that some of the assignments and our expectations of students’ work may come across as a bit “fuzzy.”
Hurricanes, Climate, and Statistics
Authors: Elsner James B. , Jagger Thomas H.
Published: November 2020

This book is about hurricanes, climate, and statistics. These topics may not seem related. Hurricanes are violent winds and flooding rains, climate is about weather conditions from the past, and statistics is about numbers. But what if you wanted to estimate the probability of winds exceeding 60 ms−1 in Florida next year. The answer involves all three, hurricanes (fastest winds), climate (weather of the past), and statistics (probability). This book teaches you how to answer these questions in a rigorous and scientific way. We begin here with a short description of the topics and a few notes on what this book is about. A hurricane is an area of low air pressure over the warm tropical ocean. The low pressure creates showers and thunderstorms that start the winds rotating. The rotation helps to develop new thunderstorms. A tropical storm forms when the rotating winds exceed 17 ms−1 and a hurricane when they exceed 33 ms−1. Once formed, the winds continue to blow despite friction by an in-up-and-out circulation that imports heat at high temperature from the ocean and exports heat at lower temperature in the upper troposphere (near 16 km), which is similar to the way a steam engine converts thermal energy to mechanical motion. In short, a hurricane is powered by moisture and heat. Strong winds are a hurricane’s defining characteristic. Wind is caused by the change in air pressure between two locations. In the center of a hurricane, the air pressure, which is the weight of a column of air from the surface to the top of the atmosphere, is quite low compared with the air pressure outside the hurricane. This difference causes the air to move from the outside inward toward the center. By a combination of friction as the air rubs on the ocean below and the spin of the earth as it rotates on its axis, the air does not move directly inward but rather spirals in a counter clockwise direction toward the region of lowest pressure.