Solid-state photooligomerization of an extended chiral bifunctional monomer, (+)-2,4:3,5-di-O-methylene-D-mannitol 1,6-di-trans-cinnamate

Abstract

Irradiation of crystalline (+)-2,4:3,5-di-0-methylene-D-mannitol 1,6-di-Znm-cinnamate (1) induces intermolecular cyclobutane formation leading to chiral oligomers of increasing length. The dimer, trimer, tetramer, and pentamer have been isolated and characterized. The intramolecular distance between the olefinic residues within the molecules of 1 is larger than in any previous examples of solid-state photodimerization or oligomerization and, in spite of the large, bulky tetraoxa-c/Tdecalin group separating the reaction centers, the cinnamate groups of the monomer are properly aligned for intermolecular photocycloaddition. Crystals of 1 are monoclinic, a = 15.218 (6) Á, b = 13.217 (7) Á, c = 5.882 (3) Á, ß = 76.95 (3)°; the space group is P2|, with two molecules in the cell. The structure has been solved by direct methods and refined to an R factor of 0.043 on 2270 nonzero reflections. The crystal structure analysis establishes the correct molecular structure of the sugar alcohol derivative, previously in doubt, and elucidates the molecular packing which is responsible for the observed products. The chemical consequences of solid-state irradiation of compound 12, a monothiophene analogue of 1, have been considered; 12, however, shows an unexpected reluctance to crystallize in the same structure as 1.

Bio-Based Aromatic Polyesters from a Novel Bicyclic Diol Derived from d-Mannitol

“…In conformation II the short distances between H X and one of the protons of the acetal methylene should be reflected in the 2D spectra with strong NOE signals, which is not the case. It is worthy to note that crystal structure studies on 2,4:3,5-di-O-methylene-D-mannitol-1,6-di-trans-cin-namate 30 established a conformation in the solid state for the bicyclic unit similar to which is determined in this work. The conclusion derived from this conformational study is that the preferred conformation of Manx is I and that this conformation is well stable; such features will confer to this monomer an enhancing stiffness effect on the polymer chain in which it is inserted.…”

Photochemical reactions in organized assemblies. 49. Topological control of reactivity by interfacial orientation: excimer fluorescence and photodimerization of 4-stilbazolium cations in aerosol Ot reversed micelles

“…The results (see Table I) show that the new derivative possesses 3 times the toxicological activity (intravenous mouse injection) and 16 times the receptor binding (rat brain membranes18) of nornicotine. Pyri- (10) Negishi, E.; Idacavage, M. J. Tetrahedron Lett. 1979, 10, 845-848.…”

“…For the higher values of in this range the major products are cis-1 and dimer 4, the products predominating in solution. As decreases, the ratio of dimers 2/4 increases sharply and the yield of c/j-1 decreases; at = [10][11][12][13][14][15][16][17][18][19][20] (Table I) the syn head-to-head dimer 2, which is not produced upon irradiation in homogeneous solution, becomes the dominant photoproduct. Quantum efficiencies for photoreaction of la and lb increase from 0.5 3 36 in dilute aqueous acid to 1.14 and 1.05 for la and lb in the reversed micelles with = 10.…”

Incorporation of flame retardancy in bio‐resourced mannitol based curing agent for clear pressure‐sensitive adhesive

“…Peaks around 4.3‐4.7 ppm are the characterized peak of the proton associated with the common carbon shared by adjacent oxygen atoms. This explains the formation of the six members in the main chain of MDM 48‐50 . Figure 2B explains the 13 C NMR of MDM.…”