3- Alkylidenephthalides

Interestingly, electrochemical reductions of alkylidenephthalides (14), which might conceivably give radicals isomeric in the heterocyclic moiety with 13, resulted either in the addition of two electrons or in ring scission, although phthalide radicals such as 15, which is not heteroaromatic, may be prepared. ... 

Alkynes. The cross-coupling of aryl halides with monosubstituted alkynes is a versatile synthetic method, and the simple substitution of THF for an amine as solvent can give significantly higher yields. With o-functionalized aryl halides the assembly of benzofurans, alkylidenephthalides, and alkylideneisoindolin-l-ones can be achieved in one or two steps. 1 - Alkynes undergo dimerization in high yields in a procedure that employs diisopropylamine. ... 

Sodium/phenol 3-Alkylidenephthalides from indan-l,3-diones... 

Several members of the Umbelliferae contain alkylidenephthalides and reduced forms of alkylidenephthalides as important odoriferous principles. The essential oil of seed from the celery plant Apium graveolens, for example, is the main source of celery odour and flavour in the perfumery... 

A complementary procedure for the preparation of ylidenebutenolides from maleic anhydrides, which has several advantages over the Grignard-and Perkin-type approaches, employs phosphoranylides. This approach was first applied in the synthesis of alkylidenephthalides e.g. 162) by reaction between phthalic anhydride and the appropriate triphenylphos-phorane 133). Interestingly, the condensations involving phosphoranes... 

Attention has already been drawn to the desirable odoriferous properties of alkylidenephthalides (13/14) and bovolide (15) and their analogues (p. 136>.. In one isolated report the synthetic ethylidenebuten-olide (226) has been reported to possess carcinogenic properties 200). 

Knight, D. W., and G. Pattenden 4-Phosphoranylidenebutenolide Intermediates in the Synthesis of 4-Ylidenebutenolides and 4-Ylidenetetronic Acids. Synthesis of Alkylidenephthalide Constituents of Celery Odour and Models for Freelingyne. J. Chem. Soc. Perkin I (London) 635 (1975). 

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