Reaction Steps
Using the same procedure employed for the preparation of 15c and using 14e (335 mg, 1.6 mmol), 2 M ethereal HCl (6 mL), PtO2 (24 mg), and ethyl acrylate (1.7 mL, 16 mmol) gave 15e (259 mg, 51%) and 17 (52 mg, 12%) following PTLC purification (10% MeOH—CHCl3). Compound 15e: reddish yellow oil; Rf 0.37 (10% MeOH—CHCl3); IR (neat) 2945, 2818, 1731, 1457, 1376, 1182 cm−1; 1H NMR (CDCl3) δ 1.18 (t, J=7.2 Hz, 3H, CH2CH3), 1.19 (t, J=7.2 Hz, 3H, CH2CH3), 1.56-1.70 (m, 4H, C(3)H2, C(4)H2), 2.15 (s, 6H, N(CH3)2), 2.26-2.48 (m, 5H, C(5)H, NCH2CH2, (CH3)2NCH2), 2.69-2.91 (m, 5H, C(2)H, C(6)H2, NCH2CH2), 4.05 (q, J=7.2 Hz, 2H, CH2CH3), 4.07 (q, J=7.2 Hz, 2H, CH2CH3), the 1H NMR assignments were consistent with the COSY spectrum; 13C NMR (CDCl3) 14.0 (CH2CH3), 14.1 (CH2CH3), 22.8 (C(3)), 25.5 (C(4)), 33.5 (NCH2CH2), 40.1 (C(5)), 46.0 (N(CH3)2), 49.3 (C(6)), 49.7 (NCH2CH2), 55.4 (C(2)), 57.7 ((CH3)2NCH2), 60.1 (2C, CH2CH3), 172.6 (C(O)), 174.2 (C(O)) ppm, the assignments were consistent with the DEPT and HMQC spectra; MS (+CI) 315 [M+1]+; Mr (+CI) 315.229 49 [M+1]+ (calcd for C16H31N2O4 315.228 38). Compound 17 (cis- and trans-mixture): Rf 0.75 (10% MeOH—CHCl3); 1H NMR (CDCl3) δ 1.00 (d, J=6.6 Hz, 2H), 1.10 (d, J=6.6 Hz, 1H), 1.21-1.28 (m, 6H), 1.44-2.00 (m, 4H), 2.21-2.30 (m, 1H), 2.42-2.59 (m, 4H), 2.67-2.88 (m, 3H), 4.08-4.17 (m, 4H).
