Spiro β-lactam thiadiazoline and triazoline systems. Comparison with the chemistry of spiro β-lactam oxadiazolines
摘要:
Triazoline, oxadiazoline, and thiadiazoline ring systems spiro-fused to C4 of a beta-lactam ring undergo 1,3-dipolar cycloreversion to form azomethine-, carbonyl-, and thiocarbonyl ylides, respectively. The order of reactivities is triazoline > thiadiazoline > oxadiazoline.