Managing Ada development

The Ada programming language was developed under the sponsorship of the Department of Defense to address the soaring costs associated with software development and maintenance. Ada is powerful, and yet to take full advantage of its power, it is sufficiently complex and different from current programming approaches that there is considerable risk associated with committing a program to be done in Ada. There are also few programs of any substantial size that have been implemented using Ada that may be studied to determine those management methods that resulted in a successful Ada project. The items presented are the author's opinions which have been formed as a result of going through an experience software development. The difficulties faced, risks assumed, management methods applied, and lessons learned, and most importantly, the techniques that were successful are all valuable sources of management information for those managers ready to assume major Ada developments projects

Interview with James Leary, October 18, 2008

James Leary was interviewed on October 18, 2008, by Sierra Green about his experiences during World War II. Course Information: Course Title: HIST 300: Historical Method Academic Term: Fall 2008 Course Instructor: Dr. Michael J. Birkner \u2772 Collection Note: This oral history was selected from the Oral History Collection maintained by Special Collections & College Archives. Transcripts are available for browsing in the Special Collections Reading Room, 4th floor, Musselman Library. GettDigital contains the complete listing of oral histories done from 1978 to the present. To view this list and to access selected digital versions please visit -- http://gettysburg.cdmhost.com/cdm/landingpage/collection/p16274coll

Cycloheptenyne dicobalt hexacarbonyl complexes by ring closing metathesis

Hexacarbonyldicobalt complexes of cycloheptenynes (4) may be prepared by the ring closing metathesis of the corresponding acyclic dienes (2) using Grubbs\u27 catalyst, (Cy3P)(2)Cl2Ru=CHPh. A cyclooctenyne complex (8) has also been prepared in the strictly analogous manner

Alkynedicobalt Complexes in γ-Carbonyl Cations and Cycloheptynedicobalt Complexes

This Account describes our work on highly electrophilic γ-carbonyl cations featuring propargyldicobalt cations, cycloheptynedicobalt complexes, and the interconnection between the two systems.1 Introduction2 γ-Carbonyl Cations via Iron Allyl Cations3 γ-Carbonyl Cations via Propargyldicobalt Cations3.1 Synthesis of Velloziolide3.2 Synthesis of Microstegiol4 Synthesis of Cycloheptynedicobalt Complexes4.1 Synthesis via γ-Carbonyl Cations4.2 Cycloheptynedicobalt Complexes via [4+3] Cycloaddition Reactions4.3 Cycloheptynedicobalt Complexes via Ring-Closing Meta­thesis4.4 Cycloaddition Reactions on Cycloheptynedicobalt Complexes4.5 Cycloheptynedicobalt Complexes via Intramolecular ­Nicholas Reactions5 Dehydrotropylium Ion Co2(CO)6 Complex6 Final Comment

Dehydrotropylium-Co2(CO)6 Ion. Generation, Reactivity and Evaluation of Cation Stability

The dehydrotropylium–Co2(CO)6 ion was generated by the action of HBF4 or BF3⋅OEt2 on the corresponding cycloheptadienynol complex, which in turn has been prepared in four steps from a known diacetoxycycloheptenyne complex. The reaction of the cycloheptadienynol complex via the dehydrotropylium–Co2(CO)6 ion with several nucleophiles results in substitution reactions with reactive nucleophiles (N\u3e1) under normal conditions, and a radical dimerisation reaction in the presence of less reactive nucleophiles. Competitive reactions of the cycloheptadienynol complex with an acyclic trienynol complex show no preference for generation of the dehydrotropylium–Co2(CO)6 ion over an acyclic cation. DFT studies on the dehydrotropylium–Co2(CO)6 ion, specifically evaluation of its harmonic oscillator model of aromaticity (HOMA) value (+0.95), its homodesmotic-reaction-based stabilisation energy (≈2.8 kcal mol−1) and its NICS(1) value (−2.9), taken together with the experimental studies suggest that the dehydrotropylium–Co2(CO)6 ion is weakly aromatic

Benzocycloheptynedicobalt complexes by intramolecular Nicholas reactions

Lewis acid mediated intramolecular Nicholas reactions of aryl (Z)-enyne propargyl acetate-CO2(CO)(6) complexes 1 afford benzocycloheptenyne-CO2(CO)(6) complexes 2 and their heterocyclic analogues

Lewis and protic acid mediated Nicholas reactions of 3-acetoxycyclohept-1-en-4-ynedicobalt hexacarbonyl: site selectivity of nucleophile incorporation

Nicholas reactions on the cation derived from the cyclic allylic acetate alkynedicobalt complex 1 favour the gamma-site kinetically for most nucleophiles, with increasing amounts of of-products in cases with greater nucleophilicity. Some regiocontrol in introduction of a specific nucleophilic fragment is possible by using different nucleophiles. Under conditions where reversibility is possible, the thermodynamically favoured site is exclusively gamma-. (c) 2005 Elsevier Ltd. All rights reserved

Activated Cyclopropanes: A Remarkable Breadth of Recent Chemistry

The reactions of cyclopropanes activated by electron-withdrawing groups and electron-donating groups – donor–acceptor (DA) cyclopropanes – and with alkenyl or alkylidene substituents has been an area of recent intense research activity. This Cluster contains contributions from many of the leading research groups in this area, and provides a concise introduction to the rich ring-opening, ring-expansion, dimerization, and cycloaddition chemistry of these compounds

Nicholas Reactions in the Construction of Cyclohepta[de]naphthalenes and Cyclohepta[de]naphthalenones. The Total Synthesis of Microstegiol

The application of the Nicholas reaction chemistry of 2,7-dioxygenated naphthalenes in the synthesis of cyclohepta[de]napthalenes and in the synthesis of (±)-microstegiol (1) is presented. The substitution profile of Nicholas monosubstitution (predominantly C-1) and disubstitution reactions (predominantly 1,6-) on 2,7-dioxygenated napthalenes is reported. Application of a 1,8-dicondensation product and selected C-1 monocondensation products to the construction of cyclohepta[de]naphthalenes by way of ring closing metathesis and intramolecular Friedel−Crafts reactions, respectively, is described. Deprotection of the C-7 oxygen function to the corresponding naphthol allows tautomerization to cyclohepta[de]naphthalene-1-ones upon seven-membered-ring closure in most cases, and replacement of the C-2 oxygen function in the naphthalene by a methyl group ultimately allows the synthesis of (±)-microstegiol

Synthesis of Tenuifolin via Intramolecular Nicholas Reaction

The synthesis of the Cinnamomum homosesquiterpenoid tenuifolin has been accomplished by way of an intramolecular Nicholas reaction of the [Co2(CO)6] complex of an alkyne-substituted biaryl for construction of the seven-membered ring. The cyclization features the reaction of a nonactivated arene ring with the propargyldicobalt cation to give the dibenzocycloheptyne-Co2(CO)6