Absolute configuration of (R)-(+)-1-methyl-2-phenylpyrrolidine

Conversion of Five-, Six-, and Seven-Membered Lactams to Racemic or Scalemic 2-Substituted Heterocycles by Amidoalkylation

“…Of these, rotations for 25b,c and 26b,c have been reported, and the absolute configurations were established by comparison. 11, [19][20][21] The rota-tions we found for these oily amines corresponded closely for 25c and 26c, 11 but not for 25b and 26b. The literature rotations of 25b and 26b were reported for neat samples obtained by resolution, but we did not make sufficient material to attempt duplication.…”

“…However, we used the sign of rotation only to establish absolute configuration. Moreover, two reports of the specific rotation of neat R-25b (both obtained by resolution) differed significantly (+13.65 19 and +156.5 20 ), but both were dextrorotatory. Enantiopurity of our compounds is assured, since the amines were obtained by reduction of single diastereomers.…”

“…( R )-1-Methyl-2-(phenyl)pyrrolidine , 25b , ,, was prepared from 22b (R = phenyl) in 65% yield as an oil after flash chromatography: 1 H NMR δ 1.25 (m, 1H), 1.63−1.98 (m, 4H), 2.15 (s, 3H), 3.01 (t, 1H), 3.32 (dt, 1H), 7.18−7.32 (m, 5H); 13 C NMR δ 22.5, 35.2, 40.5, 57.1, 71.7, 127.0, 127.5, 128.3, 143.3. [α] D + 82.5 ( c 2.0, CHCl 3 ) (lit.…”