This is a little bit off-topic, but, since you brought it up... are you familiar w/this?:
i found it in another russian book scanned and uploaded by our renowned bibliophil
Garin
"...Addition of nitrogen dioxide dimer to a double bond runs smoothly, if the latter is activated w/a phenylic ring and a carboxyl. E. g., N2O4 adds to cinnamic acid, forming a,b-dinitrohydrocinnamic acid, which upon subsequent detachment of nitrous acid and decarboxylation gives beta-nitrostyrene w/a preparative yield."
Unfortunately, no details or refs were given. Can someone suggest approximate conditions or search in the literature (PolytheneSam, Foxy2, Megamole?
) One more worrisome thing for me is if the ring-subst'd things would survive decarboxylation.
I'm not sure if it's of use - are there any other routes to cinnamic acids then via benzaldehydes?
Antoncho