The effect of bulky N‐substitutents of N‐t‐butyl‐ and N‐phenyl‐N‐allylmethacrylamides (BAMA and PAMA, respectively) on their cyclopolymerizability was investigated. BAMA yielded an almost completely cyclized polymer while the degree of cyclization of poly (PAMA) was about 95%. The latter value indicates that the effect of phenyl group is comparable with that of methyl group, since N‐methyl‐N‐allylmethacrylamide was reported to give a polymer with a degree of cyclization of 93%. Structural investigation on telomerization products of BAMA and PAMA permitted the assignment of the repeating cyclic units of these polymers to that of a five‐membered ring. This structural characteristic was also supported by the observation of five‐membered cyclized radicals on ESR measurements of these monomers. Rotation around amide CN bonds of these monomers and related compounds studied by 13C‐NMR was found to be strongly dependent on N‐substitutents. The mechanism of the cyclization was discussed in terms of the structure of the ring formed and rotation around amide CN bonds of these monomers. The reactivity of the methacryloyl and allyl groups involved in these monomers were compared based on the information obtained by structural investigation of polymers and telomerization products and by ESR studies. © 1993 John Wiley & Sons, Inc.

The possibility for five-membered ring formation, i.e., head-to-head and tail-to-tail additions, in anionic cyclopolymerization of 1,6-dienes was investigated using JV-tert-butyl-N-allylacrylamide (BAA), JV-2,6-xylyl-JV-allylacrylamide (XAA),lVJV-diallylacrylamide (DAA), and IV-methyl-N-allylacrylamide (MAA) as monomers and tert-butylmagnesium chloride as an initiator. It was found that BAA forms polymers, with five-membered rings as a repeating cyclic unit and, in addition, the degree of cyclization of poly(BAA) obtained was about 81%, in spite of the fact that the anionic polymerization tendency of an ally! group is extremely low. XAA, DAA, and MAA yielded polymers without any cyclized units leaving the allyl group as pendant unsaturation. Conformational analysis of these monomers suggested that only BAA has favorable conformation for five-membered ring formation. 13C NMR spectroscopic studies revealed that conjugations between C=C and C=0 double bonds of BAA and XAA are less effective than those of DAA and MAA probably due to steric hindrance. This indicates that the propagating anions derived from acryloyl groups of the former are more active than those of the latter. Based on these results it has been concluded that conformational advantage of BAA and higher reactivity of propagating anion derived from its acryloyl group make possible this unusual addition reaction to form five-membered ring.

The effects of smoking on the function of frontal lobe in middle-and elderlyJapanese community dwellers were examined. The participants were 477 healthy individuals aged from 40 to 86 years old (the mean was 63 years old). The letter fluency test to measure verbal executive function and the D-CAT to measure information processing speed and sustained attention were used as the measures of cognitive function which reflects prefrontal cortex function. Analyses including age and years of education as covariates indicated that the intensity of smoking tended to influence digit cancellation performances and letter fluency performance. These findings suggest that smoking may exert a deleterious long-term effect on cognitive function.

In this study, independent and interactive effects of alcohol drinking and smoking on the function of frontal lobe in middle-and elderly-Japanese community dwellers were examined. The participants were 487 health individuals aged 40 to 86 years old. The letter fluency test to measures verbal executive function, and the D-CAT to measures information processing speed and sustain of attention were used as the measures of cognitive function. Analyses including age and years of education as covariates indicated that the intensity of drinking tended to influence on information processing speed, that is, light to moderate drinkers showed good performance in comparison with abstainers or heavy drinkers. The intensity of smoking also made a significant difference on the results of the letter fluency test, and light smokers showed a higher-level performance compared with other groups.