Hydrated forms of N-[(3R)-3-(4-methyl-3,5-dioxo-1,2,4-triazolidin-1-yl)-2-methylene-butano yl]-(1S,2R)-bornane-10,2-sultam and its enantiomer

Triazolidinediones react with each enantiomeric bornanesultam derivative of tiglic acid to produce the appropriate ene adduct in high yield and with excellent regioselectivity and diastereoselectivity. The optically pure products, viz. N-[(3R)-3-(4methyl-3,5-dioxo-1,2,4-triazolidin-1-yl)-2-methylenebutanoyl ](1S,2R)-bornane-10,2-sultam 0.15-hydrate, C(18)H(26)N(4)O(5)S(.)0.35H(2)O, and its enantiomer N-[(3S)-3-(4-methyl-3,5-dioxo1,2,4-triazolidin-1-yl)-2-methylenebutanoyl ]-(1R,2S)-bornane10,2-sultam0.35-hydrate, C(18)H(26)N(4)O(5)S(.)0.35H(2)O, have been characterized by spectroscopy and single- crystal X- ray analysis. Their structures are the result of C ss-re attack of the enophile on the double bond of the alkene.