TY - STAND N1 - tert-Butyl (2R,2S)-2-Azido-3-[2,3-bis(palmitoyloxy)-propanethio]propanoate (4) Compound 4 was afforded as a very hygroscopic colourless solid (0.76 g, 74%). [α]D20 –6.31 (c 1.01, CHCl3). IR (film): νmax = 2923.3 (s, alkane CH), 2853.5 (m, alkane CH), 2114.7 (m, N3), 1740.8 (s, ester C=O) cm–1. 1H NMR (400 MHz, CDCl3): δ = 5.16 (1 H, m, CH), 4.35 (1 H, dd, J = 4.2, 3.6 Hz, CH2), 4.19 (1 H, dd, J = 5.6, 3.0 Hz, CH2), 3.98 (1 H, dt, J = 6.4, 1.2 Hz, CH), 2.87 (4 H, m, 2 × CH2), 2.31 (4 H, sext, Pam-CH2), 1.62 (br s, 4 H, Pam-CH2), 1.51 (9 H, s, 3 × CH3), 1.26 (48 H, br s, Pam-CH2), 0.88 (6 H, t, J = 6.8 Hz, Pam-CH3). 13C NMR (100 MHz, CDCl3): δ = 173.3, 173.0 (2 × CO2H), 167.7 (CO2H), 83.6 (C), 70.3 (CH), 63.4 (CH2), 62.9 (CH), 34.3, 34.1, 33.8 (Pam-CH2), 33.2 (CH2), 31.9 (CH2), 29.7–29.4 (Pam-CH2), 28.0 (3 × CH3), 24.9 (Pam-CH2), 22.7 (Pam-CH2), 14.1 (Pam-CH3). MS (ESI+): m/z (%) = 777 (25) [MNa+], 442 (100). HRMS (ESI+): m/z calcd for C42H79N3NaO6S+ [M + Na]+: 776.5582; found: 776.5544 ER -