160149-06-4

Upstream product

• 55044-06-9 methyl 2-phenyl-2-oxazoline-4-carboxylate 
• 78715-83-0 methyl (S)-2-phenyl-4,5-dihydrooxazole-4-carboxylate 
• 82936-49-0 (R)-2-phenyl-4-hydroxymethyl-4,5-dihydrooxazole 
• 160149-03-1 (RS)-4-bromomethyl-2-phenyl-4,5-dihydrooxazole 
• 825-60-5 benzimidic acid ethyl ester 
• 15263-48-6 (2-phenyl-4,5-dihydrooxazol-4-yl)methanol 

Downstream Products

• 151069-69-1 RS-2-phenyl-4-vinyl-2-oxazoline 
• 151069-89-5 (RS)-4-nitromethyl-2-phenyl-4,5-dihydrooxazole 

Relevant academic research and scientific papers

Generation and Cycloadditions of 4,5-Dihydrooxazole- and Oxazolidine-4-carbonitrile N-Oxides

A route to 2-phenyl-4,5-dihydrooxazole-4-carbonitrile N-oxide 7 has been developed starting from (S)-serine methyl ester and involving dehydration of the 4-nitromethyl derivative 13 using m-tolylene diisocyanate and triethylamine.Cycloaddition of the nitrile oxide to styrene afforded a 55:45 mixture of diastereoisomeric dihydroisoxazoles 21 and 22; furazan N-oxides 19 and 20 were also formed in a competing dimerisation.The analogous (R)-oxazolidine-4-carbonitrile oxide 8, also prepared from (S)-serine methyl ester, reacted similarly with styrene, oct-1-ene and diethyl fumarate to afford ca. 1:1 mixtures of adducts.The structures of the dihydrooxazole-dihydroisoxazole adduct 21 and furazan N-oxide 20 were determined by X-ray crystallography.

Stereoselective Cycloaddition of Nitrile Oxides to 4-Vinyl-Oxazolines and -Oxazolidines

Cycloaddition of nitrile oxides to 4-vinyl-2-oxazoline 1 and to 4-vinyloxazolidine 2 afford diastereomeric mixtures of 2-isoxazolines in which the erythro product predominates (32-64percent d.e.).In contrast, the corresponding reactions with acyclic analogue 3 favoured the threo-adducts and were less selective (8-20percent d.e.).Key Words: 1,3-dipolar cycloaddition; nitrile oxides; isoxazolines