Noland, W. E.; Gullickson, G. C.; van Lengerich, H.; Erdman, P. J.; Tritch, K. J. J. Chem. Crystallogr. 2017, 47, 80.
Agnotobenzaldehyde was first reported by Dr. Eugen Bamberger in 1906, from a Zn-promoted reduction of 2-nitrobenzaldehyde. He determined the empirical formula to be C14H12N2O5. Subsequent work determined the chemical structure of the solution form by IR and NMR analysis, but the structure of the crystal form remained inconclusive. In the present work, the structure of crystalline agnotobenzaldehyde has been found to be rac-(3R)-1-[(S)-hydroxy(2-nitrophenyl)methyl]-1,3-dihydro-2,1-benzisoxazol-3-ol. Crystals are orthorhombic with the Pbca space group. At 173(2) K, a = 13.8066(14), b = 8.4412(9), c = 22.832(2) Å, and V = 2660.9(5) Å3 with Z = 8. Poly(O–H⋯) C44(8) chains of alternating intra- and inter-molecular hydrogen bonds form along the b axis. These chains probably affect the regio- and diastereo-specificity of cyclization.