INTRAMOLECULAR ALKOXYMERCURATION OF OLEFINS AND STABILIZATION OF THE RESULTING ORGANOMERCURIALS

Quenching of oxymercuration with CuCl has been found superior to the c lassical method using aqueous NaCl or KBr. Oxymercuration products wit h an antiperiplanar arrangement of the C-HgX and C-O bonds (e.g. diaxi al as in 2) are particularly prone to reversion to the olefin (1) when treated with hard reagents, such as NaCl, KBr, CuCl2, CoCl2, HCl, etc . The reversal is apparently boosted by the stereoelectronic effect an d electrophilic catalysis. By contrast, quenching of the primarily for med organomercurial 2 with soft reagents, namely with CuCl, PdCl2 K2Pt Cl4, etc. reliably affords the desired chloromercury compound 3.