Abstract
The reactions of the active phosphacumulenes, (2-oxovinylidene)-(7a) and (2-thioxovinylidene)triphenylphosphorane (7b) with several o-(8, 12, 14, 16) and p-quinones (18, 20, 22, 24) have been studied. Phosphoranylidene-cyclobutanediones (11a, 13a, 15a, 17a, 19a, 21a, 23a, 25a) and dithioxo-cyclobutylidenes (11b, 13b, 15b, 17b, 19b, 21b, 23b, 25b) were obtained and identified on the basis of elemental analysis and spectroscopic studies.