Compound \[A,{{C}_{5}}{{H}_{10}}{{O}_{5}}\]gives a tetraacetate with \[A{{c}_{2}}O\] and oxidation of 'A' with \[B{{r}_{2}}/{{H}_{2}}O\] gives an acid, \[{{C}_{5}}{{H}_{10}}{{O}_{6}}\]. Reduction of 'A' with \[HI\]gives iso-pentane. What is the possible structure of A?