Hexahydro-8-isoquinolones with electron-acceptor substituents in position 4

Abstract

Derivatives of hexahydro-8-isoquinolone with electron-acceptor substituents (nitro or ethylthiocarbonyl groups) in position 4 represent a group of compounds that have not been investigated adequately, namely hydrogenated nitrogen heterosystems containing a/3-aminovinylcarbonyl structural fragment in which the keto group is f'Lxed in the s-cis-configuration with respect to the double bond. In the work reported here, we synthesized and studied new representatives of this class of compounds. In the electronic spectra of compounds IIIa,b,c, which were synthesized here for the first time, there are long-wave absorption bands with maxima at 455, 448, and 421 nm, respectively ( Table 1) -bands that are characteristic for compounds of the hexahydroisoquinolone series [2]. In the spectra of compound IIIc, we found a 23-nm bathochromic shift of the longwave maximum relative to the oxygen-containing analog, indicating a stronger conjugation of the ethylthiocarbonyl substituent with the/3-aminovinyl system [2, 4].

Aliphatic aldehydes in the synthesis of carbo- and heterocycles: Part II. Synthesis of six- and seven-membered rings, bicyclic compounds, and macrocycles

“…Tetrahydropyridines 77 were synthesized by highly diastereoselective aza-silyl-Prins reaction of aldehydes 1b, 1d, 1h, 1j, and 1l with silylated homoallylamines 76 [80][81][82] [85], or B(C 6 F 5 ) 3 [86] and under microwave [87] or ultrasonic activation [88]. Alkyl-substituted dihydropyridines thus formed were found to exhibit diverse biological activity [89][90][91][92][93][94]. The process may be illustrated by general Scheme 22.…”