Dean M. Moren

The chemistry of 2-alkenyl-5(4H)-oxazolones. VIII acid-catalyzed reaction with alcohols

Abstract The acid-catalyzed reaction of 4,4-dimethyl-2-vinyl-5(4H)-oxazolone with primary alcohols proceeded with almost equal frequency at both CC (Michael addition) and CO (ring opening) groups; reaction with secondary and tertiary alcohols resulted in a modest elevation in Michael addition. Michael addition was not observed in reactions with 4,4-dimethyl-2-isopropenyl-5(4H)-oxazolone.

A One-Pot Transformation of Ketones Into N-(Meth)Acryloyl-2-Amino Acids

Abstract A synthetic sequence for the preparation of N-(meth)acryloyl-2-amino acids is outlined which involves transformation of a ketone successively into an aminonitrile and a (meth)acrylamidonitrile, followed by selective hydrolysis of the nitrile function. All reactions are performed in aqueous media, in one reaction vessel, and in a stepwise manner without isolation of any intermediate products.

The Chemistry of 2‐Alkenyl‐5(4H)‐ oxazolones. IX. Acid‐Catalyzed Oligomerization

Abstract Results of the acid catalyzed oligomerization of 2‐alkenyl‐5(4H)‐oxazolones are reported. Employing LC–MS and preparative LC methods, the oligomeric mixtures were characterized by NMR analyses and were discovered to consist of exclusively cyclic trimers to decamers, with tetramers and pentamers predominating. A nucleophilic oligomerization mechanism involving Michael addition and C‐alkylation of a ketene‐aminal to protonated monomer was proposed that resulted in irreversible cyclization at the trimer propagation stage. Subsequent oligomerization proceeded via enolization of α‐hydrogens on 2‐substituted 5(4H)‐oxazolone products and continued Michael addition to protonated monomer. In the sense that when both enolizable hydrogens and protonated monomer are present, the oligomerization can be regarded as being “living.”