Syntheses and crystal structures of two di­naph­tho[2,1-d:1′,2′-f][1,3]dithiepine atropisomers

The closely related title compounds, 1-(di­naphtho­[2,1-d:1′,2′-f][1,3]dithiepin-4-yl)-2,2-di­methyl­propan-1-ol, C(26)H(24)OS(2), 1 and 2-(di­naphtho­[2,1-d:1′,2′-f][1,3]dithiepin-4-yl)-3,3-di­methyl­butan-2-ol, C(27)H(26)OS(2), 2, both comprise an atrop­isomeric binaphthyl di­thio­acetal unit substituted at the methyl­ene carbon atom with a chiral neopentyl alcohol grouping. The overall stereochemistry of the racemate in each case is defined as aS,R and aR,S. In 1, the hydroxyl group generates inversion dimers via pairwise inter­molecular O—H⋯S hydrogen bonds whereas in 2, the O—H⋯S link is intra­molecular. Weak C—H⋯π inter­actions link the mol­ecules into extended arrays in both structures.