The crystal structures and Hirshfeld surface analysis of 6-(naphthalen-1-yl)-6a-nitro-6,6a,6b,7,9,11a-hexahydrospiro[chromeno[3′,4′:3,4]pyrrolo[1,2-c]thiazole-11,11′-indeno[1,2-b]quinoxaline] and 6′-(naphthalen-1-yl)-6a′-nitro-6′,6a′,6b′,7′,8′,9′,10′,12a′-octahydro-2H-spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizin]-2-one

Abstract

The title compounds, 6-(naphthalen-1-yl)-6a-nitro-6,6a,6 b,7,9,11a-hexahydrospiro[chromeno[3′,4′:3,4]pyrrolo[1,2-c]thiazole-11,11′-indeno[1,2-b]quinoxaline], C37H26N4O3S, (I), and 6′-(naphthalen-1-yl)-6a′-nitro-6′,6a′,6b′,7′,8′,9′,10′,12a′-octahydro-2H-spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizin]-2-one, C36H28N2O4, (II), are new spiro derivatives, in which both the pyrrolidine rings adopt twisted conformations. In (I), the five-membered thiazole ring adopts an envelope conformation, while the eight-membered pyrrolidine-thiazole ring adopts a boat conformation. An intramolecular C—H...N hydrogen bond occurs, involving a C atom of the pyran ring and an N atom of the pyrazine ring. In (II), the six-membered piperidine ring adopts a chair conformation. An intramolecular C—H...O hydrogen bond occurs, involving a C atom of the pyrrolidine ring and the keto O atom. For both compounds, the crystal structure is stabilized by intermolecular C—H...O hydrogen bonds. In (I), the C—H...O hydrogen bonds link adjacent molecules, forming R22(16) loops propagating along the b-axis direction, while in (II) they form zigzag chains along the b-axis direction. In both compounds, C—H...π interactions help to consolidate the structure, but no significant π–π interactions with centroid–centroid distances of less than 4 Å are observed.

Keywords

• crystal structure
• nitrogen-containing heterocycles
• chromen
• spiro compounds
• cycloaddition
• piperidine
• pyran
• pyrrolidine
• hydrogen bonding
• C—H...π interactions
• Hirshfeld surface analysis