Scheme 4a.
aReagents and conditions: (a) (MeOCH2CH2)2NSF3, Et3N, CH3(CH2)4NH2, 0 °C, 15 min, then rt, 2 h, 70%; (b) SOCl2, 1H-benzotriazole, CH2Cl2, rt, 20 min; (c) CH3(CH2)2SH, pyridine, CH2Cl2, rt, 3 h, 23%, two steps.
aReagents and conditions: (a) (MeOCH2CH2)2NSF3, Et3N, CH3(CH2)4NH2, 0 °C, 15 min, then rt, 2 h, 70%; (b) SOCl2, 1H-benzotriazole, CH2Cl2, rt, 20 min; (c) CH3(CH2)2SH, pyridine, CH2Cl2, rt, 3 h, 23%, two steps.