6-Chloro-1-(triphenyl-lambda~5~-phosphanylidene)hexan-2-one → [(tetrahydro-2H-pyran-2-ylidene)methyl]triphenylphosphonium chloride

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Reaction Steps

A solution containing 20 parts of (5-chloropentanoylmethylene)triphenylphosphorane in 200 parts of benzene is heated at the reflux temperature for about 16 hours. Cooling of this solution results in crystallization of a product which is isolated by filtration to afford [(tetrahydro-2H-pyran-2-ylidene)methyl]triphenylphosphonium chloride. This product is characterized by 60-MHz nuclear magnetic resonance peaks in CDCl3 (deuterated chloroform) at about 107 cps (multiplet), 170 cps (multiplet), 228 cps (multiplet) and 329 cps (doublet, J≃ 18 cps) in addition to the aromatic protons. This compound melts at about 215°-221° C. and is represented by the following structure: ##STR8##

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