10160-87-9Relevant articles and documents
A CONVENIENT ROUTE TO ALKYNES VIA PHASE TRANSFER CATALYSIS; ( APPLICATIONS OF PHASE TRANSFER CATALYSIS, PART 19 )
Dehmlow, Eckehard V.,Lissel, Manfred
, p. 1653 - 1658 (1981)
High yield, rapid formations of alkynes from vic-dibromides are possible using powered potassium hydroxide and catalytic amounts of lipophilic phase transfer catalysts.Reasons are given why molar amounts of expensive catalysts were necessary in earlier procedures.
Reactive carbon-chain molecules: Synthesis of 1-diazo-2,4-pentadiyne and spectroscopic characterization of triplet pentadiynylidene (H-C≡C-C- C≡C-H)
Bowling, Nathan P.,Halter, Robert J.,Hodges, Jonathan A.,Seburg, Randal A.,Thomas, Phillip S.,Simmons, Christopher S.,Stanton, John F.,McMahon, Robert J.
, p. 3291 - 3302 (2006)
1-Diazo-2,4-pentadiyne (6a), along with both monodeuterio isotopomers 6b and 6c, has been synthesized via a route that proceeds through diacetylene, 2,4-pentadiynal, and 2,4-pentadiynal tosylhydrazone. Photolysis of diazo compounds 6a-c (λ > 444 nm; Ar or N2, 10 K) generates triplet carbenes HC5H (1) and HC5D (1-d), which have been characterized by IR, EPR, and UV/vis spectroscopy. Although many resonance structures contribute to the resonance hybrid for this highly unsaturated carbon-chain molecule, experiment and theory reveal that the structure is best depicted in terms of the dominant resonance contributor of penta-1,4-diyn-3- ylidene (diethynylcarbene, H-C≡C-C-C≡C-H). Theory predicts an axially symmetric (D∞h) structure and a triplet electronic ground state for 1 (CCSD(T)/ANO). Experimental IR frequencies and isotope shifts are in good agreement with computed values. The triplet EPR spectrum of 1 (|D/hc| = 0.6157 cm-1, |E/hc| = 0.0006 cm-1) is consistent with an axially symmetric structure, and the Curie law behavior confirms that the triplet state is the ground state. The electronic absorption spectrum of 1 exhibits a weak transition near 400 nm with extensive vibronic coupling. Chemical trapping of triplet HC5H (1) in an O2-doped matrix affords the carbonyl oxide 16 derived exclusively from attack at the central carbon.
Versatile methodology to synthesize oxygen-bridged nine- and ten-membered cycloalkanes by the hypoiodite reaction
Montana, Angel M.,Ponzano, Stefano,Kociok-Koehn, Gabriele,Font-Bardia, Merce,Solans, Xavier
, p. 4383 - 4401 (2007)
C-3 derivatives of 6-hydroxy-2,7-dimethyl-11-oxatricyclo[6.2.1.0 2,6]undecan-4-one reacted with lead tetraacetate (LTA) and iodine to afford, in good yield, 1,7-epoxycyclononanes, which are the result of a β-fragmentation of the C2-C6 bond adjacent to the tertiary hydroxy group on C-6. This β-fragmentation is followed by a ring contraction from a ten- to a nine-membered ring system, by a free-radical addition to the carbonyl group on C-4. The reaction of precursors (not functionalized on C-3) with LTA and iodine produced a β-fragmentation without any further structural rearrangement, affording 1,8-epoxycyclodecanes. The transformation of the carbonyl group on C-4 to acetate avoided radical additions and rearrangements affording, in high yield, the corresponding cyclodecanes. By this methodology, either 1,7-epoxycyclononane or 1,8-epoxycyclodecane could be synthesized, in good yield, by choosing the appropriate substitution pattern on C-3 in the substrate. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Sequential and tandem oxidation/acetalization procedures for the direct generation of acetals from alcohols
Smith, Brendan M.,Graham, Andrew E.
, p. 4891 - 4894 (2007)
Alcohols are transformed directly into either acyclic or cyclic acetals in both tandem and sequential oxidation/acetalization processes using manganese dioxide, trialkyl orthoformates and catalytic quantities of indium triflate.
Propynal equivalents and diazopropyne: Synthesis of all mono-13C isotopomers
Seburg, Randal A.,Hodges, Jonathan A.,McMahon, Robert J.
experimental part, p. 1626 - 1643 (2009/10/17)
Mechanistic and spectroscopic investigations of reactive C 3H2 hydrocarbons necessitated the preparation of diazopropyne isotopomers bearing mono-13C substitution at each of the three unique positions. The diazo compounds and their tosylhydrazone precursors were prepared from the mono-13C isotopomers of propynal (in the form of either the aldehyde or the diethyl acetal). The introduction of 13C-labeling at either alkyne position in propynal utilized the Corey - Fuchs procedure for chain homologation.
