Reactions of ethoxycarbonylmethylene(triphenyl)phosphorane with some ortho-quinones in the presence of triphenylphosphine, alcohols and acetic anhydride

Abstract

The reactions of ortho-quinones 1a, 1c and 1d with ylide 2 in the presence of triphenylphosphine afforded the ylides 11a, 11c and 11d and compound 12. The reactions of 1a and 1c with 2 in refluxing methanol or ethanol gave compounds 16 and 17 respectively, while the reactions of 1a–d with 2 in acetic anhydride yielded the acetates 18a, 18b, 18d and 19b, 19d, the furan derivative 24 and the ylide 25. Compounds 8 and 9 were also obtained in most of the above reactions. Wittig reactions of ylides 11a, 11c with p-nitrobenzaldehyde and of ylide 2 with coumarins 8a and 29 resulted in compounds 14a, 14c, 26 and 30 respectively. The transformations of compounds 18, 19 into 8, 9 as well as of compound 26 into 28 were also studied.