(S)-N-[(S)-1-Hydroxy-4-methyl-1,1-diphenylpentan-2-yl]pyrrolidine-2-carboxamide

(S)-N-[(S)-1-Hydroxy-4-methyl-1,1-diphenylpentan-2-yl]pyrrolidine-2-carboxamide (5) is obtained as a single isomer (by ¹H and ¹³C NMR) and has the following physical and spectroscopic properties: mp 197-199 °C; [a]_D²⁰ -51.6 (c 1.00, CHCl₃) 
lit.: [a]_D²⁵ -46 (c 1.2, CHCl₃)]; 
<sup>Org. Lett. 2006, 8, 4097-4099

1</sup>H NMR pdf(CDCl ₃, 600 MHz) 
d: 0.86 (d, J = 6.7 Hz, 3 H), 0.91 (d, J= 6.5 Hz, 3 H), 1.19-1.25 (m, 2 H), 1.42-1.49 (m, 2 H), 1.54-1.59 (m, 3 H), 1.86-1.92 (m, 2 H), 2.56 (dt, J = 10.0, 6.1 Hz, 1 H), 2.82 (dt, J = 9.9, 6.4 Hz, 1 H), 3.48 (dd, J = 9.3, 4.2 Hz, 1 H), 4.58 (t, J = 9.8 Hz, 1 H), 5.45 (br. s, 1 H), 7.12 (t, J = 7.3 Hz, 1 H), 7.18 (t, J = 7.4 Hz, 1 H), 7.24 (t,J = 7.5 Hz, 2 H), 7.30 (t, J = 7.6 Hz, 2 H), 7.55 (t, J = 7.6 Hz, 4 H), 7.94 (d, J = 8.0 Hz, 1 H); 

¹³C NMR pdf(CDCl ₃, 150 MHz) d: 21.5, 23.8, 25.3, 25.7, 30.4, 37.5, 46.9, 56.5, 60.2, 80.8, 125.6, 125.7, 126.3, 126.5, 127.8, 128.1, 145.1, 146.5, 175.9; 

IR (ATR): 3466, 3275, 3069, 2955, 2868, 1634, 1513, 1494, 1446, 1100, 1060, 885, 744 (s), 700 (s), 640 cm^-1;


 Anal. Calcd for C₂₃H₃₀N₂O₂: C, 75.37; H, 8.25; N, 7.64. Found: C, 75.55; H, 7.98; N, 7.74. 


established the enantiomeric purity of 5 thus obtained by conversion into (+)- and (–)-MTPA amides Several sets of diagnostic peaks are observed without cross-over, proving the enantiomeric purity of the final product 5. [MTPA amide derived from (+)-MTPACl: ¹H NMR (CDCl₃, 600 MHz) d: 0.90 (d, J = 6.9 Hz, 3 H, (CH₃)₂CH-)), 1.07 (d, J = 6.4 Hz, 3 H, (CH₃)₂CH-)), 3.60 (s, 3 H, CH₃O-); MTPA amide derived from (–)-MTPACl: ¹H NMR (CDCl₃, 600 MHz) d: 0.89 (d, J = 6.6 Hz, 3 H, (C H₃)₂CH-)), 0.98 (d, J = 6.4 Hz, 3 H, (CH₃)₂CH-)), 3.70 (s, 3H, CH₃O-).









see

 Pure (S)-2-amino-4-methyl-1,1-diphenylpentan-1-ol (2) can be obtained by recrystallization from EtOAc and has the following physical and spectroscopic properties: colorless crystals; mp 134-137 °C; [a]_D²⁰-91.6 (c 1.00, CHCl₃) lit.: [a]_D²⁵ -96.6 (c 1.00, CHCl₃)]; 

<sup>Zhou, Z.; Guo, Y. Synth. Commun. 2008, 38, 684-696


1</sup>H NMR pdf(CDCl₃,600 MHz) d: 0.87 (d, J = 6.4 Hz, 3 H), 0.89 (d, J = 6.4 Hz, 3 H), 1.06-1.11 (m, 1 H), 1.27 (ddd, J = 14.3, 10.4, 3.8 Hz, 1 H), 1.54-1.59 (m, 1 H), 2.31 (brs, 3 H), 3.98 (d, J = 10.4 Hz, 1 H), 7.14-7.19 (m, 2 H), 7.27 (t, J = 7.4 Hz, 2 H), 7.31 (t, J = 7.7 Hz, 2 H), 7.48 (d, J = 6.8 Hz, 2 H), 7.61 (d, J = 7.6 Hz, 2 H); 


¹³C NMR pdf(CDCl₃, 150 MHz) d: 21.3, 24.0, 25.3, 39.4, 54.5, 79.1, 125.5, 125.8, 126.3, 126.6, 128.0, 128.4, 144.5, 147.1;

 IR (ATR): 3337, 3264, 2953, 2866, 1586, 1490, 1469, 1448, 1384, 1181, 1057, 1005, 903, 743 (s), 695 (s), 639 cm^-1; 

Anal. Calcd. for C₁₈H₂₃NO: C, 80.26; H, 8.61; N, 5.20. Found: C, 80.36; H, 8.82; N, 5.15.