Direct formation of methylenecyclopentanes by cycloaddition of a

Jul 1, 1972 - The chemistry of trimethylenemethanes, a new class of biradical reactive intermediates. Jerome A. Berson. Accounts of Chemical Research ...
0 downloads 0 Views 230KB Size
5508

Scheme I

Ph,+.,N Ph

N, ’Ph

-kP

nonconcerted 1,3-sigmatropic rearrangement (e.g., 3 + 5 + 4). Moreover, the cycloadditions are of potential importance in synthesis as a direct route to methylenecyclopentanes.

h - N H w & P h

Ph

5

4

X,

4 + 5 -

+

a

1

Ph N

N

w

6

N

,

p

+

h

TFA

-----*

7

H P

7(or8) 6

+

base

-

+

h

-

excessTFA

N

w

-

-N