Oxazolo-oxazine derivs. - which are bi:cyclic hemiacetal cpds. prepd. by reacting alpha-di:ketone cpds. with di:ethanolamine derivs.

摘要

New bicyclic hemiacetal derivs. are cpds. of formula (I): where R1, are aliphatic, cycloaliphatic, aromatic or araliphatic residues, or R1 and R2 are linked so as to form an alicyclic ring; and R3 is H or an aliphatic, cycloaliphatic, roamtic or araliphatic residue. Specific cpds. (I) include 8,9-tetramethylene-8-hydroxy-perhydrooxazolo 2,3-c 1,4 oxazine. In an example, this is prepd. in 81% yield by refluxing 1,2-cyclohexanedione with diethanolamine in toluene in the presence of p-toluenesulphonic acid. Intermediates for dyes, pesticides and pharmaceuticals.