EXTREMELY REACTIVE CARBON-CARBON DOUBLE BONDS-I; REACTIONS WITH 2-(9-XANTHYLIDENE)-, 2-(9-THIOXANTHYLIDENE)-, AND 2-(9-FLUORENYLIDENE)-INDANE-1,3-DIONE. A CONTRIBUTION ON THE STRUCTURE AND REACTIVITY OF NON-PLANAR C-C DOUBLE BONDS

Article abstract of DOI:10.1016/S0040-4020(01)91970-2

The compounds in the title (cf 1a, 1b and 2) react with various reagents, often under mild conditions, mostly by breaking of the central double bond.According to X-ray diffraction the central double bond of 2-(9-xanthylidene)indane-1,3-dione is inclined by 47.2 deg.The relationship between the structure and reactivity of the compounds in the title is discussed.