154663-55-5

Upstream product

• 186581-53-3 diazomethane 
• 154663-57-7 (E)-2-phenyl-4-<(S)-2,2-dimethyl-1,3-dioxolan-4-ylmethylen>-5(4H)-oxazolone 
• 154663-54-4 (Z)-4-<(S)-2,2-dimethyl-1,3-dioxolan-4-ylmethylidene>-2-phenyl-1,3-oxazol-5(4H)-one 
• 1707-77-3 1,2:5,6-di-O-isopropylidene-D-mannitol 
• 70775-39-2 dimethylsulfoxonium methylide 

Relevant academic research and scientific papers

Study of the Reaction of a Chiral Oxazolone with Oxosulphonium Methylides as Cyclopropanating Agents

The behaviour of the chiral Z-oxazolone derived from 1,2-O-isopropylidene-D-glyceraldehyde towards oxosulphonium methylides as cyclopropanating agents has been studied.The solvent and temperature dependence of the ratio of the products is described.

1,3-Dipolar cycloaddition of diazomethane to chiral azlactones. Experimental and theoretical studies

The reaction of (E)-2-phenyl-4-[(S)-2,2-dimethyl-1,3-dioxolan-4- ylmethylen]-5(4H)-oxazolone with diazomethane has been studied under a variety of reaction conditions, and the results compared with those obtained with the corresponding (Z)-isomer. The origin of the high diastereofacial selectivity in the cyclopropane products, observed with both oxazolones, is discussed in the light of theoretical calculations of the first reaction step, i.e., the 1,3-dipolar cycloaddition of diazomethane, carried out at the semiempirical (AM1) and ab initio (RHF/3-21G) levels. Both theoretical levels correctly predict the direction of the asymmetric induction in the concerted reaction pathway leading to the Δ1-pyrazoline. AM1 calculations predict also the existence of a stepwise reaction pathway leading to an open-chain reaction intermediate, which is not supported by the ab initio results.

Atmospheric pressure chemical ionization multi-stage mass spectrometry in the characterization of stereoisomeric synthons of cyclopropane amino acids

The mass spectrometric behaviour of (1S,2R)-, (1R,2R)-, (1R,2S)- and (1S,2S)-2-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]-1-spiro-{4'[2'-phenyl-5'(4'H)-oxazolone]} cyclopropane (2) and (1S,2R)-, (1R,2R)-, (1R,2S)- and (1S,2S)-methyl-1-benzamido-2-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]cyclopropanecarboxylate (3) was studied under atmospheric pression ionization conditions and by multi-stage mass spectrometric (MS(n)) experiments performed with an ion trap. Interestingly, by using methanol as solvent, compounds 2 lead to [M + H + CH3OH]+ ions which, as proved by collisional experiments, exhibit the same structure of the corresponding compound 3. MS/MS of [MH]+ ions allows a clear characterization of the different stereoisomers, which give rise to specific fragmentation pathways, rationalized with respect to the structure of the neutral molecules. Copyright (C) 2000 John Wiley and Sons, Ltd.

1,3-Dipolar Cycloaddition of Diazomethane with a Chiral Azlactone

The chiral Z-azlactone derived from 1,2-O-isopropylidene-D-glyceraldehyde reacted with diazomethane to afford stereoselectively and diastereoselectively a cis spiro-azlactone.Solvent and temperature dependence of the ratio of the products is described.