Photochemical decarboxylation of 9-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-non-4-ynoic acid, 12-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-dodec-5-ynoic acid, 14-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-tetradec-12-ynoic acid and 16-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-hexadec-5-ynoic acid yield N-heterocycles in moderate yields. The macrocyclic compounds were obtained by photolysis at 300nm varying the chain length and the position of triple bond of the starting materials. With the short methylene chain in $\omega$ -phthalimidoalkynoate, it was difficult to obtain the cyclized product but as the methylene chain gets longer and the triple bond is placed far away from the phthalimide group, the photocyclized products were obtained in moderate to fair yields.
9-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-non-4-ynoic acid, 12-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-dodec-5-ynoic acid, 14-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-tetradec-12-ynoic acid 그리고 16-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-hexadec-5-ynoic acid 을 광화학적으로 탈카르복실레이션시키면 광고리화 반응으로 N-헤테로 고리화합물이 얻어진다. 이 고리화합물들은 출발 화합물들의 메틸렌사슬과 삼중결합의 위치를 변화시켜 300nm의 파장에서 광반응시켜 얻었다. 메틸렌사슬의 길이가 짧은 경우에는 고리화합물이 얻어지지 않았으나, 사슬이 길어짐에 따라 그리고 삼중결합의 위치가 프탈이미드기로부터 멀어짐에 따라 고리화합물이 비교적 높은 수율로 얻어졌다.
