Syntheses of derivatives of oestrane and 19-norsteroids from 6-methoxytetralone and 6-hydroxytetralone

Synthesis of antiproliferative 13α-d-homoestrones via Lewis acid-promoted one-pot Prins–Ritter reactions of d-secosteroidal δ-alkenyl-aldehydes

“…The inhibition of proliferation by the homosteroids (6-11) depended considerably on the structures of the compounds (Table 2). In the case of the N-acetyl derivatives (6,9), the main stereoisomer (6a, 9a) proved to be less potent than the minor bridged product (6b, 9b) in both the 3-benzyl and 3-methyl ether series. Table 2 The cancer selectivities of the selected potent compounds (9b and 10a) were tested by means of the MTT assay, using the non-cancerous human fibroblast cell line MRC-5.…”

“…One of the approaches to the D-homolog of estrone is total synthesis, which was first reported by Ananchenko et al [6]. A new simple methylene homologation for estrone was described by Liu et al, who used lithium trimethylsilyl diazomethane, followed by treatment with silica gel [7].…”

“…Found: C, 77.18; H, 8.05%.16β-N-benzoyl-3-benzyloxy-13α-D-homoestra-1,3,5(10)-trien-17aα-ol (11a) and 3-benzyloxy-(2'-phenyl-16α,17aα-dihydro-17H-1',3'-oxazine-16-yl-17a-yl)-13α-D-homoestra-1,3,5(10)-triene (11b)The crude product derived from the cyclization of 2 was purified by flash chromatography with EtOAc/CH 2 Cl 2 = 15/85 as eluent. The first-eluted 11b was obtained as an oil (88 mg, 18%), R f = 0,6 (ss C); 1 H NMR (DMSO-d6 ) δ H 1.25 (s, 3H, 18-H 3 ), 2.69 (m, 2H, 6-H 2 ), 3.68 (s, 1H, 16-H), 4.04 (s, 1H, 17a-H), 5.01 (s, 2H, OCH 2 ), 6.64 (s, 1H, 4-H), 6.75 (dd, 1H, J = 8.4 Hz, J = 1.6 Hz, 2-H), 7.06 (d, 1H, J = 8.6 Hz, 1-H), 7.30 (t, 1H, J = 7.1 Hz, 4'-H), 7.35-7.47 (overlapping multiplets, 7H, 2"-H, 3'-H, 3"-H, 4"-H, 5'-H, 5"-H, 6"-H), 7.88 (d, 2H, J = 7.8 Hz, 2'-H and 6'-H). 13 C NMR (DMSO-d 6 ): δ C 25.0, 25.9, 26.0, 27.3 (C-18), 29.6, 30.0, 34.7, 38.5 (C-13), 38.9, 39.0, 43.9 (C-16), 45.4, 68.9 (OCH 2 ), 80.0 (C-17a), 112.30).…”

Highly Regioselective Oxygenation of C−H Bonds: Diamidomanganese Constructs with Attached Substrates as Catalyst Models

“…[5,7,12] The preferred formation of knot 5 over formation of a topologically isomeric catenane or the non-knotted topologically isomeric macrocycle (with 12 CONH groups each) is attributed to hydrogen bonds between amide groups, as in comparable template syntheses of catenanes and rotaxanes. [12,13] Instead of the usual macrocyclic tetralactam host (of type 3) the middle loop of the knot could, however, act as a noncyclic concave template for a CONH guest group. [14] Molecular trefoil knots, for which we propose the name ªknotanesº, are topologically chiral, and in some cases Sauvage succeeded in the resolution of racemates.…”

“…Interestingly, the Mn II complex 5 provided ketone 4 as the major product, a result similar to the known oxidation of 2-acetoxytetralin with CrO 3 . [12] Presumably, the C À H bonds at position 5 are more electron rich, and hence more vulnerable to electrophilic metal oxidants. In contrast, such electronic preferences are completely overridden by restricting the approach of the substrate to the metal center.…”