A Widely Applicable Method of Resolution of Binaphthyls: Preparation of enantiomerically Pure 1,1'-Binaphthalene-2,2'-diol, 1,1'-Binaphthalene-2,2'-dithiol, 1,1'-Binaphthalene-2-ol-2'-thiol and 1,1'-Binaphthalene-8,8'-diol

Here, we present a new method of resolution of la and 2a based on the facile separation of the pair of diastereoisomers lb and 2b derived from the reaction of either la or 2a with 2 mol of (-)-menthyl chloroformate (3). The method appears to be generally applicable to the binaphthyl systems, in as much it was proved possible to prepare and separate with ease the diastereoisomers derived from the reaction of 3 with many other derivatives such as the mixed system 4a and , -binaphthalene-8,8'-diol (5a).