ChemInform Abstract: INTRAMOLECULAR SIMMONS-SMITH REACTION AND OTHER SYNTHETIC ALTERNATIVES TO CYCLOPROPANATION OF DIENIC DIAZO KETONES. PARALLEL DECOMPOSITION PATHWAYS OF A STERICALLY CONGESTED DIAZO KETONE AND ITS VINYLCYCLOPROPANE UNDER THERMAL, PHOTOL

1985 ◽  
Vol 16 (22) ◽  
Author(s):  
T. HUDLICKY ◽  
B. C. RANU ◽  
S. M. NAQVI ◽  
A. SRNAK
Keyword(s):  
Parallel Decomposition ◽  
Diazo Ketone

Carbon–Carbon Bond Construction

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Organic Synthesis ◽  
Grignard Reagent ◽  
Secondary Amide ◽  
State University ◽  
Wayne State University ◽  
Carbon Carbon Bond ◽  
Diazo Ketone ◽  
Peking University ◽  
Subsequent Exposure ◽  
The University

Carlo Siciliano and Angelo Liguori of the Università della Calabria showed (J. Org. Chem. 2012, 77, 10575) that an amino acid 1 could be both protected and activated with Fmoc-Cl, so subsequent exposure to diazomethane delivered the Fmoc-protected diazo ketone 2. Pei-Qiang Huang of Xiamen University activated (Angew. Chem. Int. Ed. 2012, 51, 8314) a secondary amide 3 with triflic anhydride, then added an alkyl Grignard reagent with CeCl3 to give an intermediate that was reduced to the amine 4. John C. Walton of the University of St. Andrews found (J. Am. Chem. Soc. 2012, 134, 13580) that under irradiation, titania could effect the decarboxylation of an acid 5 to give the dimer 6. Jin Kun Cha of Wayne State University demonstrated (Angew. Chem. Int. Ed. 2012, 51, 9517) that a zinc homoenolate derived from 7 could be transmetalated, then coupled with an electrophile to give the alkylated product 8. The Ramberg-Bäcklund reaction is an underdeveloped method for the construction of alkenes. Adrian L. Schwan of the University of Guelph showed (J. Org. Chem. 2012, 77, 10978) that 10 is a particularly effective brominating agent for this transformation. Daniel J. Weix of the University of Rochester coupled (J. Org. Chem. 2012, 77, 9989) the bromide 12 with the allylic carbonate 13 to give 14. The Julia-Kocienski coupling, illustrated by the addition of the anion of 16 to the aldehyde 15, has become a workhorse of organic synthesis. In general, this reaction is E selective. Jirí Pospísil of the University Catholique de Louvain demonstrated (J. Org. Chem. 2012, 77, 6358) that inclusion of a K+-sequestering agent switched the selectivity to Z. Yoichiro Kuninobu, now at the University of Tokyo, and Kazuhiko Takai of Okayama University constructed (Org. Lett. 2012, 14, 6116) the tetrasubstituted alkene 20 with high geometric control by the Re-catalyzed addition of 19 to the alkyne 18. André B. Charette of the Université de Montréal converted (Org. Lett. 2012, 14, 5464) the allylic halide 21 to the alkyne 22 by displacement with iodoform followed by elimination. In an elegant extension of his studies with alkyl tosylhydrazones, Jianbo Wang of Peking University added (J. Am. Chem. Soc. 2012, 134, 5742) an alkyne 24 to 23 to give 25.

The influence of parallel decomposition strategies on the performance of multiprocessor systems

1985 ◽  
Vol 13 (3) ◽  
pp. 396-405 ◽  
Author(s):  
Dalibor Vrsalovic ◽  
Edward F. Gehringer ◽  
Zary Z. Segall ◽  
Daniel P. Siewiorek
Keyword(s):  
Multiprocessor Systems ◽  
Parallel Decomposition ◽  
Decomposition Strategies

Thermolysis of Δ3-1,3,4-oxadiazolin-2-ones and 2-phenylimino-Δ3-1,3,4-oxadazolines derived from α,β-epoxyketones. An alternative method for the convers of α,β-epoxyketones to alkynones and alkynals

1978 ◽  
Vol 56 (3) ◽  
pp. 308-315 ◽  
Author(s):  
Gerald A. MacAlpine ◽  
John Warkentin
Keyword(s):  
Carbonyl Compounds ◽  
Polar Solvents ◽  
Parallel Decomposition ◽  
Alternative Method ◽  
Aldehydes And Ketones ◽  
Decomposition Pathway

Thermolyses in polar solvents, of Δ3-1,3,4-oxadiazolin-2-ones or 2-phenylimino-Δ3-1,3,4-oxadiazolines derived from α,β-epoxyketones, yields acetylenic carbonyl compounds. Good yields of acetylenic aldehydes and ketones are obtained for those cases in which the epoxide is ring fused. Extension to acyclic cases failed primarily due to predominance of a parallel decomposition pathway. The method complements the procedures developed by Eschenmoser and co-workers for the conversion of, α,β-epoxyketones into acetylenic carbonyl compounds.

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