Improved preparation of (1S,3′R,4‘S,5′S,6’R)-5-chloro-6-[(4-ethylphenyl)methyl]-3′,4′,5′,6′-tetrahydro-6′-(hydroxymethyl)-spiro[isobenzofuran-1(3H),2′-[2H]pyran]-3′,4′,5′-triol - Liu, Y H; Fu, T M; Ou, C Y (Chin Chem Lett, 2013)