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We have synthesized several Meldrum's acid derivatives using Diels-Alder reaction as a key step. Here, the key sultine derivative is prepared by rongalite and the sultine derivative is useful as a latent diene.Meldrum's acid, 2,2-dimethyl-1,3-dioxane-4,6-dione, a cyclic ester, with an acidic CH2 group with pKa 4.83 1,2 is valuable synthon to design heterocycles and polycycles. 3 It is widely used in multicomponent reactions. 4 Meldrum's acid derivatives are also beneficial to assemble natural products and also used for synthesis of reactive intermediates and polymers. 5 They are also used in aza-Diels-Alder reaction with different dienophiles. 6 Uracil derivatives 7 are synthesized from trifloroacetyl Meldrum's acid. Gillena and co-workers 8 recently synthesized an antimicrobial compounds from Meldrum's acid. Various Meldrum's acid derivatives 1-5, shown in Figure 1 are useful in designing diverse polycycles. 9-18 Figure 1. Meldrum's acid derivatives used in organic synthesisRecently, Kotha and co-workers reported diverse Meldrum's acid derivatives involving a [2+2+2] cycloaddition reaction as a key step. Compound 4 undergo ring-closing metathesis (RCM) to generate cyclopentene derivative 6. Whereas, dialkyne derivative 5 and monoalkyne 7 undergo cyclotrimerization to generate the dibromo compound 8 with the aid of Mo(CO)6 (Scheme 1) under microwave irradiation conditions in acetonitrile. 19,20 Furthermore, we developed a new route for the synthesis of tetrahydroisoquinoline carboxylic acid derivatives via a [2+2+2] cyclotrimerization. 21,22 In view of our

We report various unusual amino acid derivatives containing heterocycles and heteroatoms (S, O, N) via diethyl acetadimalonate as a glycine equivalent and carried out further chemical transformations to modify these unusual amino acid derivatives. Sulfur‐containing halo and alkene derivatives are prepared, and these substrates are further modified by Suzuki‐Miyaura cross‐coupling reaction, cross metathesis sequence and selective formation of sulfoxide and sulfone derivatives. We also report oxazole‐containing amino acid derivative by using TosMIC.

Here, we report various unusual amino acid derivatives containing bicyclo[2.2.2]octane unit through the Diels-Alder (DA) reaction as a key step. DA reaction was carried out with pentacene as a diene and different dinenophiles used here are derived by dehydration of serine derivatives.