Figure 3:
Reagents and reaction conditions: (a): hν, CH
2
Cl
2
, 25°C, 30 min (quant.); (b) AcOH/H
2
O/TFA (2.5/1/0.6), THF, 25°C, 1.5 h [
10
(19%),
11
(15%),
12
(25%)].
