“…On the other hand, in the similar copolymerization of 3b with la, the unit ratio of 3b increased to ca. 20 % with increase of the feed ratio of 3b (from 25 to 67 %) [Table I (entries [9][10][11][12], Figure 2 (•)]. Of course, 2b or 3b alone (feed ratio 100%) gave no polymer as they had no homopolymerizability.2 Therefore, the order of copolymerizability toward la is lb » 3b > 2b, in good agreement with the order of the strain energy of the SOEs, lb » 3b > 2b.…”