Synthesis and Resolution of 7,7'-Dimethyl-2H,2'H-3,3'-Spirobis[benzofuran]-4,4'-diol

1,1′-Spirobiindane-7,7′-diol (SPINOL) is a privileged scaffold in asymmetric catalysis. The modulation of the SPINOL skeleton via the replacement of one carbon atom with a more electronegative oxygen atom would lead to unique properties because of the shorter bond length (C−O bond) and wider bite angle. However, synthetic methods for oxa-spirocyclic diphenol (O-SPINOL) remains limited. Herein, we report a convenient synthetic route to synthesize O-SPINOL derivative in four steps from 5-methoxy-2-methylphenol. Both enantiomers can be easily accessed on large scale through resolution by preparative high performance liquid chromatography (PHPLC).