VINYLOGOUS DIECKMANN CONDENSATION: AN APPLICATION OF BALDWIN'S RULES.

Article abstract of DOI:10.1016/S0040-4039(01)81218-1

Vinylogous Dieckmann condensations equivalent to enolexo-exo-trig and enolendo-exo-trig cyclisations have been investigated.Five membered rings were smoothly obtained from the former whereas the latter cyclisations occured with six but not with five membered rings.

Full text of DOI:10.1016/S0040-4039(01)81218-1

2512
Interestingly, a recent attempt at a very similar ring opening reaction was reported to be
unsuccessful, and the authors regarded the failure of the reaction as due to a disfavoured
1 1
cyclisa t ion ”.
To conclude, the vinylogous Dieckmann condensation of the various systems described here have
all been found to strictly obey Baldwin’s rules.
rules be given consideration when synthetic strategies are being planned. Certainly, the
It is, therefore, good precaution that the
rules should not be regarded as
FOLLY.”
ACKNOWLEDGEMENT:
We thank The National Research Council
work.
for the support of this
REFERENCES
1.
1976, 734.
2.
3.
4.
5.
J .E.Baldwin,
W.V.P h illips,
J .E.Baldwin, L.I.Kruse,
SARKOMYCIN
1953, 101
Tetrahedron, 1982,
2939.
1978,
700.
1977, 233.
Examples are
Y.Yamamoto,
METHYLENOMYCIN A
1974,
D.A.Hopwood, Tetrahedron Lett., 1978, 2977).
T.Siwapinyoyos, 1982, 598.
386
A
6.
7.
8.
All products described here gave satisfactory physical data.
Very recently a cyclisation similar to the
process has been reported
M.Panunzio, 1983,
and the reported system,
However, there are marked differences between
including the reaction conditions employed.
9. 15 was prepared by alkylation of the
introduction of the double bond, while 11 was obtained from our previous work
1983 3553
(single compound, stereochemistry not known) was prepared in a similar manner starting
from 10
10 withmethyl 6-bromocrotonate followed by
10.
11.
12.
III,
1980,
3 9 0 4 .
J r .,
Compare with ref. 8
that I have enunciated
quotation taken from
Ciba Foundation Symposium 53,
which
have
Perspectives in Organic
1979,
be
(Received in UK 27 March 1984)