MOLECULAR MODELING, A TOOL FOR PREDICTING STRUCTURAL EFFECTS ON THE MACROCYCLIZATION REACTION BETWEEN BIS(VINYL OR ALLYL) DIALDEHYDES AND THIOPHOSPHONIC BIS(HYDRAZIDES)

The reaction of new phosphorus dialdehydes PhP(O)[(CH2)(n)CH=CHC6H4CHO ](2) (4a-c, 5a) (n = 0:4, n = 1:5; a:para, b:meta, c:ortho), with thio phosphonic bis(hydrazide) PhP(S)[NMeNH(2)](2) (6) yields macrocyclic c ompounds 9b', c', 10a', 9a'', b'', c'', 10a'' and 9c''', arising from cyclocondensation of one, two, or three equivalents of each reagent, r espectively. Molecular modeling of 4a-c, 5a, 6 and of the intermediate monocondensation products 7a-c, 8a was carried out and points out the importance of the geometry of the starting reagents in the competitio n between inter- and intra-molecular cyclocodensation.