Recent Syntheses and Reactions of Cyclic Imidic Esters

Abstract

Abstract Δ 2 ‐Oxazolines and 4H‐5,6‐dihydrooxazines are readily obtainable from carboxylic acids and 2‐ or 3‐amino alcohols by gas‐phase dehydration, and 4H‐dihydrooxazines can also be obtained by condensation of N‐(hydroxymethyl) carboxamides with olefins. These cyclic imidic esters undergo reactions in which the ring is cleaved; these reactions include a new type of polymerization. The behavior of alkyl groups in position 2 and the cyclodditions in the 2,3‐position also have been studied. Reactions in side chains on position 2 and addition experiments on the sulfur analogues of the cyclic imidic esters are also reported. A table shows the principal infrared bands of substituted Δ 2 ‐oxazolines.