Page 1005 - Advanced Organic Chemistry Part B - Reactions & Synthesis

Scheme 10.19. Radical Cyclizations with Tandem Alkylation 981
H
OC 2 5
SECTION 10.3
OC H
2 5
1 a O Reactions Involving Free
OCHCH I O Radical Intermediates
2
3 3
Bu SnCl, NaBH Si(CH )
+ CH 2 CC(CH 2 ) 4 CH 3 3 4
hv C(CH ) CH 3
2 4
Si(CH ) R SiO 60%
3 3
SiO 2 O
R 2
2 b I
CH 2 CH 3 CH 2
Bu SnH CH 3 H
(CH ) CCH 2 CH 3 3
3 2
80°C
CH 3
CH CH C CH CH 3 H 64%
2
2
3 c
CH 3 Bu SnH CH 3 H S
3
C 6 H 5
C H C(CH CH CH ) O
2 2
2
6 5
CH S COCH 2 AIBN CH 3
3 2
CH CH 71%
CH 2 2
4 d O CO C H
2 2 5
C H
CO 2 2 5 CO C H
ICH CNC CH 2 Ph SnH 2 2 5
3
2
O
N O N
+
61%
O O 26%
5 e CH 3 CH 3 CCH Bu SnH CH 3 CCH 3
3
3
H
O CH O CH
I
H
TBDMSO H CH CH OTBDMS
CH 3 2 2
93%
) Si
)
6 f Si(CH 3 3 (CH 3 3
I (C H ) B, 2 equiv H H
2 5 3
C H I, 0.25 equiv I
2 5
O O O
O 2 O
H H H 74%
7 g
CH 2
Bu SnH CH 2 S
3
N
C O N
CH 3 80°C
O
CH 3 S CH 3 CH 3 69%
8 h CH
H CH H 3
3
THPO Bu SnH
3
CH 2 AIBN THPO
CH 3 80°C
H H
O CH 3 O
99%
Br
OC H
H 2 5
OC 2 5
(Continued)