Azasteroids. V. The Direct Conversion of 1-(Carboethoxymethyl)-1,2,3,4-tetrahydroisoquinolines and Cyclic Ketones into Benzo[a]cycloalkano[f]quinolizinones. An Example of Enamine Acylation by an Ester Function^1,2

Novel synthesis of 8-Aza Steroids

“…Protonation of enamino ketones on treatment with acid has been reported with a number of aza steroids. [15][16][17][18] The properties reported for these compounds compare well with those observed for 8a and 8b.…”

Synthesis of Simple Enantiopure Tetrahydro-β-carbolines and Tetrahydroisoquinolines

“…The obtained products are almost pure, so in most cases chromatography is not For the synthesis of the enantiopure tetrahydroisoquinoline 31 the imine 30 was prepared by condensation of 28 with 29 in the presence of SnCl 4 to give 30 in 92% yield (Scheme 5). [15] Surprisingly, in this reaction only the imine is formed; the corresponding enamine was not found. Enantioselective hydrogenation of 30 with (R,R)-5 gave (1S)-31 in 85% yield and 99% ee.…”

Ab + D → Abd → Abcd

“…For example, the condensation of the isoquinoline derivative 195 (Scheme 4-22, R = C0 2 Et) with cyclopentanone furnished the Scheme 4-22 enamine 196, which was cyclized to the 12-keto steroid 197. * Methylation and catalytic hydrogénation produced the methyl ether (198) of 8-aza-3-hydroxy-l,3,5(10)-estratrien-12-one [147,153]. The 8-azasteroid 200 (n = l,2) was similarly synthesized by heating the amine ester 199 and the ketone in refluxing toluene [154].…”