Knoevenagel reaction physical properties

The domino process probably involves the chiral enamine intermediate 2-817 formed by reaction of ketone 2-813 with 2-815. With regard to the subsequent cy-doaddition step of 2-817 with the Knoevenagel condensation product 2-816, it is interesting to note that only a normal Diels-Alder process operates with the 1,3-bu-tadiene moiety in 2-817 and not a hetero-Diels-Alder reaction with the 1-oxa-l,3-butadiene moiety in 2-816. The formed spirocydic ketones 2-818/2-819 can be used in natural products synthesis and in medidnal chemistry [410]. They have also been used in the preparation of exotic amino adds these were used to modify the physical properties and biological activities of peptides, peptidomimetics, and proteins... [Pg.175]

To a mixture of an aromatic carbonyl compound (1 2.0 mmol) and an active methylene compound (2 2.0 mmol) in 10 mL of dry toluene (in case of most of the entries) was added 0.05 g of soUd activated catalyst MHT at room temperature. The reactitMi mixture was then stirred for stipulated time (0.5 to 4 h) to complete the reaction. The Knoevenagel product was obtained in excellent yield after usual work-up and proper purification. Physical and spectral properties of all the products were found to be identical when compared with those of authentic samples. After completion of each reaction, the soUd catalyst was filtered off followed by its activation before further use. [Pg.7]

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