Chemistry of Phosphorus Ylides, 11 [1] Reactions with Phosphacumulenes, V: The Reaction of Phosphoranes with Hydroxyxanthenone and Hydroxyquinoline Mannich Bases. Novel Synthesis for Pyranones, Pyranthiones, Phosphoranylidenes

The reaction o f 1-hydroxyxanthenone (1) and hydroxyquinoline (10, 13) Mannich bases with the reactive phosphacumulated ylides (2), represents a new way for the synthesis o f the pyranones and pyranthiones (5, 11, 14). On the other hand, the stabilized phosphorus ylides (6) affect the transylidation o f the Mannich base (1) to the corresponding phosphoranylidenes (9). The structure o f the resulting new compounds has been confirmed through elemental anal­ ysis and spectroscopic results (IR, ’H, 3IP N M R and MS).