4491-48-9

Upstream product

• 186581-53-3 diazomethane 
• 4491-47-8 2-phenyl-4-isopropylidene-5(4H)oxazolone 
• 43083-57-4 (Z)-4-ethylidene-2-phenyloxazol-5(4H)-one 
• 37791-41-6 4-ethylidene-2-phenyl-5-oxazolone 

Downstream Products

• 552337-17-4 1-benzoylamino-2,2-dimethyl-cyclopropanecarboxylic acid methyl ester 
• 552337-18-5 1-(benzoyl-tert-butoxycarbonyl-amino)-2,2-dimethyl-cyclopropanecarboxylic acid methyl ester 

Relevant academic research and scientific papers

Cyclopropane analogue of valine: Influence of side chain orientation on peptide folding

The cyclopropane analogue of valine (1-amino-2,2-dimethylcyclopropanecarboxylic acid, c3Val) has been synthesised and incorporated into the model peptides tBuCO-L-Pro-L-c3Val-NHiPr and tBuCO-L-Pro-D-c3Val-NHiPr. In the solid state, both dipeptides accommodate a type II β-turn stabilised by an NHiPr to tBuCO hydrogen bond. Remarkably, the peptide incorporating L-c3Val also exhibits a distorted γ-turn around the cyclopropane residue, with Pro-CO and NHiPr intramolecularly hydrogen-bonded.

Reaction of 4-Methylene-5(4H)-oxazolones With Diazomethane

The reaction of diazomethane with some (E) and (Z)-2-substituted-4-methylene-5(4)-oxazolones (1a-c) under two different conditions, has been studied. (E) and (Z)-1,2-disubstituted-7-oxo-6-oxa-4-azaspiro-hept-4-enes (3a-c, 4a-c) were mainly obtained, together with multiple addition compounds.The reaction showed to be stereoselective only when the substituents were aromatic.Acid hydrolysis of compounds 3a and 4a produced a mixture of (E) and (Z)-3,5-disubstituted-tetrahydrofuran-2-ones (8a, 9a).Smooth methanolysis of the ring led to (E) and (Z)-1-benzamido-cyclopropanecarboxylic esters (10a-c, 11a-c), which, on acid hydrolysis, gave (E) and (Z)-1-amino-2-phenylcyclopropanecarboxylic acids 12a and 13a.The pmr spectra have been analyzed by an iterative computer method, and the computed best values obtained have been used to deduce the stereochemistry of the spiroderivatives.