  We propose the pure natural quintessential inflation model which is motivated
by Witten's conjecture, where the axion couples to pure Yang-Mills $SU(N)$
gauge field at large N limit. This modifies the standard cosine potential which
is presented in the natural inflation, making it compatible with current CMB
data. Our model gives a successful inflation as well as acceleration at the
late times by quintessence inflaton field($\phi$). Here the inflaton field is
responsible for inflation, after that the field enters into peculiar type of
reheating and then they act as dynamical dark energy field which follows the
same inflation potential and same model parameters. The dynamical field slowly
rolls until the Hubble drops to mass of the quintessence field and it reaches
the current dark energy field value. Here the dark energy scale is field
dependent. Our quintessence model follows thawing frozen approach therefore the
frozen quintessence field evolves with respect to cosmic time from initial
field value($\phi_{i}$) to present non-zero minimum field value($\phi_{0}$).
The obtained field value turned into ultra-light and it satisfies the present
dark energy density which is $V(\phi_{0}) \approx \Lambda_{\text{DE}}^{4} =
(2.3 \times 10^{-3}\text{eV})^{4}$.
