Helical Poly(α,β‐unsaturated ketone) with Bulky Pendant of Binaphthyl from Anionic Polymerization of ((−)‐Menthyl (S)‐6′‐Acrylyl‐2′‐methyloxy‐1,1′‐binaphthalene‐2‐carboxylate

((−)-Menthyl (S)-6′-acrylyl-2′-methyloxy-1,1′-binaphthalene-2-carboxylate (3) was synthesized and anionically polymerized using n-BuLi as an initiator in toluene. The monomer 3 was levorotatory and had an [α]D25 value of −72.4, but its corresponding polymer poly-3 was dextrorotatory and showed an [α]D25 value of +162.0. Poly-3 was confirmed to exist in the form of one-handed helical structure in solution by means of comparing the specific optical rotation and the CD spectra with that of 3 and the model compounds such as (−)-menthyl (S)-6′-propionyl-2′-methyloxy-1,1′-binaphthalene-2-carboxylate 2b and (−)-menthyl (S)-6′-heptanoyl-2′-methyloxy-1,1′-binaphthalene-2-carboxylate 2c. This conclusion was also confirmed by the fact that the g-value of poly-3 is about 11 times of that of monomer 3.