Topochemistry. Part XIX. The crystal structure of monomethyl trans,trans-muconate

Abstract

The crystal structure of monomethyl trans,trans-muconate has been solved from the photographically recorded (hk0) and (h0l) reflections, and refined to r= 0·015, R= 0·063. The bond lengths have been determined with an e.s.d. of 0·02 Å. The structure consists of stacks of hydrogen-bonded molecule pairs (O⋯O 2·62 Å); double bonds of nearest-neighbour molecules make contact along the short c-axis, and these are presumably responsible for the photochemical formation of cyclobutanes. Interstack contacts of 3·6 Å between terminal atoms of the butadiene chain may account for the initiation of polymerisation.