aReagents: a) p-cresol, Et3N, CH2Cl2, -10 ° - 0 °C, 30 min; b) benzyl alcohol, Et3N, 0 °C, 1h; c) N-methyl-N-(2-bromo-ethyl)amine hydrobromide, Et3N, THF, 20 min, rt;d) N-methyl-N-(4-bromobutyl)amine hydrobromide, i-Pr2NEt, CH2Cl2, -20 °C to rt, 4 hr; e) p-cresol, LiHMDS, THF; f) nitrofurfuryl alcohol, LiHMDS, THF