Crystal structures of 5,5′-bis(­hydroxy­methyl)-3,3′-biisoxazole and 4,4′,5,5′-tetrakis­(hydroxy­methyl)-3,3′-biisoxazole

The mol­ecular structure of 5,5′-bis(­hydroxy­methyl)-3,3′-biisoxazole, C(8)H(8)N(2)O(4) (1), is composed of two trans planar isoxazole rings [r.m.s deviation = 0.006 (1) Å], each connected with a methyl hydroxyl group. Similarly, the structure of 4,4′,5,5′-tetrakis­(hydroxy­methyl)-3,3′-biisoxazole, C(10)H(12)N(2)O(6) (2), is composed of two planar isoxazole rings [r.m.s. deviation = 0.002 (1) Å], but with four hydroxymethyl groups as substituents. Both mol­ecules sit on a center of inversion, thus Z′ = 0.5. The crystal structures are stabilized by networks of O—H⋯N [for (1)] and O—H⋯O hydrogen-bonding inter­actions [for (2)], giving rise to corrugated supra­molecular planes. The isoxazole rings are packed in a slip-stacked fashion, with centroid-to-centroid distances of 4.0652 (1) Å for (1) (along the b-axis direction) and of 4.5379 (Å) for (2) (along the a-axis direction).