organic compounds
The crystal structures of the title compounds, C20H30O3 (I) and C16H22O3 (II), are described. The benzocyclobutene rings in (I) and (II) are approximately planar. The lengths of the Csp3-Csp3 bonds in the cyclobutene rings of (I) and (II) are 1.659 (2) and 1.596 (2) Å, respectively. The C-C bond elongation observed in (I) may be ascribed to steric congestion and/or electronic effects on the bond exerted by the methyl groups and the alkyl side chain attached to the cyclobutenol moiety, together with a ring strain expected for a four-membered ring system.