Biomedical Engineering Reference
In-Depth Information
SCHEME 5.21
Domino cyclopropanation/Cope rearrangement of trienone
50
. (Adapted
from [26], with permission; copyright
C
2009 American Chemical Society.)
After reaction optimization, this domino cyclopropanation/Cope rearrangement
sequence could be applied to the benzamide-containing trienone
53
to afford a sepa-
rable mixture of diastereomers
54a
:
54b
(1 : 1.4) in good overall yield (Scheme 5.22).
Based on this methodology, a library of hydroazulenoisoindoles was prepared
(Scheme 5.23) [25b]. Eight trienone analogs
55
, prepared as reported previously
[25a], were subjected to the domino cyclopropanation/Cope rearrangement sequence
and yielded a total of 10 cycloheptadiene analogs
56
(44 to 75%). Further struc-
tural diversity was introduced via Diels-Alder cycloadditions with six readily avail-
able dienophiles, affording 40 hydroazulenoisoindoles
57
as single diastereomers
(Table 5.14).
SCHEME 5.22
Domino cyclopropanation/Cope rearrangement of trieneone
53
. (Adapted
from [26], with permission; copyright
C
2009 American Chemical Society.)