Kawsari Akhter

Synthesis of Substituted Tetrahydrochromenes by the Reactions of α,β-Unsaturated Cyanoesters with Dimedone/1,3-Cyclohexanedione

Abstract Ethyl esters of 2-cyano-3-arylacrylic acid 1a–d (a = 4-CH3-C6H4-, b = 4-N(CH3)2-C6H4-, c = 2-CH3O-C6H4-, d = 2-Cl-C6H4-) reacted with 5,5-dimethyl-1,3-cyclohexanedione (2p, Y=CH3), and 1e–g (e = 4-CH3-C6H4-, f = 2-CH3O-C6H4-, g = 2-Cl-C6H4-) reacted with 1,3-cyclohexanedione (2q, Y=H) in the presence of alcoholic sodium ethoxide to give the corresponding ethyl esters of 2-amino-7,7-dimethyl-5-oxo-4-aryl-5,6,7,8-tetrahydro-4H-chromene-3-carboxylic acid 4a–d and 2-amino-5-oxo-4-aryl-5,6,7,8-tetrahydro-4H-chromene-3-carboxylic acid 4e–g. The structures of the compounds 4a–g were confirmed by their ultraviolet, infrared, 1H NMR, 13C NMR, and mass spectral data and elemental analyses.

Synthesis of some substituted adamantane-2,4-diones from 4, 4-disubstituted cyclohexanone enamines and methacryloyl chloride

The reaction of methacryloyl chloride with the morpholine enamine 4a derived from 4-acetyl-4-isopropenylcyclo-hexanone 3a gave 4,6-anti-6-hydroxy-5,6-dimethyl-7-isopropenyladamantane-2,4-dione 6a and 4,6-syn-6-hydroxy-5,6-dimethyl-7-isopropenyladamantane-2, 4-dione 7a as racemates epimeric at 6-C. Comparable results were found for the corresponding phenyl and benzyl substituted cyclohexanones 3b and 3c. In the case of the methyl-substituted cyclohexanone 3d 4,6- anti-alcohol 7d was isolated in pure form.

Synthesis of substituted tricyclo[5.3.1.04,9]undecan-2,6-dione from 4,4-disubstituted cyclohexanone enamines and methacryloyl chloride

Abstract Morpholine enamines 4‐acetyl‐4‐methyl‐1‐morpholinocyclohexene 4a, 4‐acetyl‐4‐phenyl‐1‐morpholinocyclohexene 4b, and 4‐acetyl‐4‐isopropenyl‐1‐morpholinocyclohexene 4c react with methacryloyl chloride to give 1,7‐dimethyl‐4(N‐morpholino) tricyclo[5.3.1.04,9]undecan‐2,6‐dione 9a , 1‐phenyl‐7‐methyl‐4(N‐morpholino) tricyclo[5.3.1.04,9]undecan‐2,6‐dione 9b , and 1‐ispropenyl‐7‐methyl‐4(N‐morpholino) tricyclo[5.3.1.04,9]undecan‐2,6‐dione 9c respectively, along with the corresponding substituted adamandane‐2,4‐diones.