Stereospecific synthesis of highly substituted novel carbasugar as carbonic anhydrase inhibitors: decahydronaphthalene-1,2,3,4,5,6,7-heptol

Decahydronaphthalene-1,2,3,4,5,6,7-heptol, a new polycyclitol, was synthesized starting from p-benzoquinone. An endo selective Diels-Alder cycloaddition between p-benzoquinone and 1-acetoxybutadiene followed by stereoselective reduction with NaBH4/CeCI3 center dot 7H(2)O led to the formation of an allylic cis-diol. The formed diol was converted into its acetate with Ac2O/pyridine, in a transformation that required inert atmosphere conditions to suppress a competing aromatization. Controlled oxidation by OsO4 of two olefinic bonds followed by acetylation yielded the heptaacetate whose structure was established unequivocally via application of X-ray crystallographic methods. Removal of the acetate groups by NH3 provided the target heptol. In addition, the carbonic anhydrase inhibitory potency of the title compound was investigated and it was shown to be a potent inhibitor compared to the standard CA inhibitors. (C) 2014 Elsevier Ltd. All rights reserved.