Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... A new prostacyclin analog, 4,4,5,5-tetradehydro-9(0)-methano-gD 6 (9α)-PGI, has been synthesized by utilizing the regiocontrolled cleavage of the β-propiolactone uith the dialkylaluminum acetylide. ... PMR(CDCl 3 )δ(ppm): 5.87 (broads, 1H), 4.5~4.7(m, 1H), 3.70(s, 3H), 2.60( ...