Write the structure of the following compound.
$2$-Hydroxycyclopentane carbaldehyde

Write the structure of the following compound.

$4$-Oxopentanal

Write the structures of products of the following reaction:

Write the structures of products of the following reaction:

${\left({\mathrm{C}}_6{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2\right)}_2\mathrm{C}\mathrm{d}+2\mathrm{C}{\mathrm{H}}_3\mathrm{C}\mathrm{O}\mathrm{C}\mathrm{l}\mathrm{}⟶$

Write the structures of products of the following reaction:

${\mathrm{H}}_3\mathrm{C}-\mathrm{C}\equiv \mathrm{C}-\mathrm{H}\stackrel{\mathrm{H}{\mathrm{g}}^{2+}, {\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4}{\to }$

Write the structures of products of the following reaction: