Scheme 1:
Reagents and conditions: (a) Et
3
N, CH
2
Cl
2
, MeSO
2
Cl; (b) Ac
2
O, concentrated HNO
3
; (c) 2% NaOH, Me
2
SO
4
; (d) Pd/C, H
2
, MeOH; (e) Pyridine, substituted sulfonyl chlorides, 0°C.
