A tactical 1,3-dipolar cycloaddition approach for the synthesis of carbohydrate derived polycyclic spiro heterocycles

Recent advancement in the synthesis of diverse spiro-indeno[1,2-b]quinoxalines: a review

“…71,72 Chromenes are important classes of heterocycles because of their core being incorporated in a large variety of natural products and biologically active compounds. 73,74 Raghunathan et al 75 have introduced a structurally unique sugar and chromene based dipolarophile hybrid, namely (4-oxo-2-glyco-4H-chromene-3-carboxylate) 71, and accomplished a 3 + 2 cycloaddition reaction with dipoles generated in situ by the reaction of indenoquinoxalinone 3 and a-amino acids such as sarcosine 16a, L-proline 16d, and pipecolinic acid 16f in the presence of base NaOMe to produce the corresponding glyco polycyclic spiroindenoquinoxalines 72-74, respectively. The dipolarophile was synthesized by the reaction of glyconitroalkene 69 with 4-hydroxycoumarin 70 in the presence of Et 3 N and methanol (Scheme 43).…”

Recent Advances in the Synthesis of Hetero- and Carbocyclic Compounds­ and Complexes Based on Acenaphthylene-1,2-dione

“…Later, Rao and Raghunathan 19 synthesized dipolarophile 41 from D-glucose. This dipolarophile reacted with in situ generated azomethine ylides to give carbohydrate-derived spiroheterocycles 43-46 in 78%, 81%, 74% and 72% yields, respectively, as single regioisomers through 1,3-dipolar cycloaddition methodology (Scheme 14).…”

Current Trends towards the Synthesis of Bioactive Heterocycles and Natural Products Using 1,3-Dipolar Cycloadditions (1,3-DC) with Azomethine Ylides

“…Proline 1, sarcosine (13), tetrahydroisoquinolinic acid 42, or piperidine-2-carboxylic acid (14) and acenaphthoquinone (33), isatin (2), or indenoquinoxalinone 43 were employed in this cascade protocol to access a variety of biologically important spiroheterocyclic compounds 41 as single diastereoisomers. 24 Regio-and diastereoselective 1,3-DC also afforded dispirooxindolepyrrolidines in a similar way, but employing 3-(arylmethylene)-5-phenyl-3Н-furan-2-ones 44, 25 or 3′-aryl-5′-arylmethylenespiro[2H-indole-3,2′-thiazolidine]-2(1H)4′-diones 45 as dipolarophiles (Scheme 10). 26 Other potential bioactive dispirooxindole derivatives 48 were described by Mondal and co-workers from N-benzylglycine (46) and isatins 2 or acenaphthoquinone (33) with andrographolide (47), isolated from Andrographis panicula- Other α-amino acid derivatives used…”