55320-94-0Relevant academic research and scientific papers
Electron Impact Mass Spectrometry of 2-Hydroxymethyl-3,4,5,6,7,8-hexahydro-2H-1-benzopyran-5-ones. The Unusual Presence of + Species in the Fragmentation Pattern of 4-Phenyl Derivatives
Bravo, Pierfrancesco,Ticozzi, Calimero,Traldi, Pietro
, p. 444 - 447 (1982)
The mass spectrometric behaviour of some 2-hydroxymethyl-3,4,5,6,7,8-hexyhadro-2H-1-benzopyran-5-ones is described and discussed with the aid exact mass measurements, linked scans, labelling experiments and low electron energy measurements.The unusual presence of abundant + species in the mass spectra of 4-phenyl substituted compounds is discussed in detail and a mechanism is proposed.
Cationic rhodium(I)/bisphosphane complex-catalyzed isomerization of secondary propargylic alcohols to α,β-enones
Tanaka, Ken,Shoji, Takeaki,Hirano, Masao
, p. 2687 - 2699 (2008/02/08)
We have determined that hydrogenated cationic Rh(I)/bisphosphane complexes are highly active catalysts for the isomerization of secondary propargylic alcohols to α,β-enones. A kinetic resolution of secondary propargylic alcohols proceeded with moderate selectivity with [Rh((R)-BINA-P)]OTf as a catalyst. Mechanistic studies revealed that the isomerization proceeds through intramolecular 1,3- and 1,2-hydrogen migration pathways. The isomerization of propargylic diol derivatives was also investigated, which revealed that 1,4-diketones, furans, and α,β-enones were obtained from 2-butyn-1,4-diol, 1-methoxy-2-butyn-4-ol, and 1-acetoxy-2-butyn-4-ol derivatives, respectively. Furthermore, chemoselectivity of the isomerization of an acetylenic diol was investigated, and preferential oxidation of a propargylic hydroxy group was observed. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
