5
522
D.M. Rudzinski et al. / Tetrahedron Letters 50 (2009) 5520–5522
The energy of stacking for 1(tBu) with toluene was by far the
sition of dialkoxy disulfides. Current studies are underway on the
ortho and meta-substituted bis(benzyloxy) disulfides to see how
their rates and product ratios may be altered.
highest with 318.00 kcal/mol. This can most likely be attributed
to the steric bulk of the tert-butyl group. Similarly, 1(Ph) possesses
a relatively high stacking energy (52.616 kcal/mol) due to the twist
of the biphenyl, increasing the steric interactions of the system.
The lowest stacking energy was observed with 1(Cl) (7.772 kcal/
Acknowledgments
mol), which possesses not only pi-stacking but also a LPCl
–
p
inter-
We thank Niagara University and the Niagara University Aca-
demic Center for Integrated Science for financial support. MPM
would like to thank the National Science Foundation, James Cum-
mings Foundation, and GeNYsis for additional financial support.
1
5
action. Graphing the experimental ratio versus the inverse of the
total energy demonstrates a linear relationship (Fig. 4). This shows
that there is a correlation between pi-stacking and product ratios,
thus supporting Harpp’s cage mechanism model.8
We have examined the thermolytic decay of a range of para-
substituted bis(benzyloxy) disulfides (1). Their rates of decomposi-
tion were all first order, and their rate constants (k ) were corre-
d
lated to Swain and Lupton’s field constant, F. The ratio of
alcohol to aldehyde obtained for this series of compounds provides
further evidence for the cage mechanism of thermolytic decompo-
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Figure 4. Relationship of ratio of alcohol to aldehyde with the total energies of the
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