Convert the following:

Explanation

The `(-CHO)` group is protected by glycol [aldehyde is more reactive than `(gt C==O)` group).]

ii.
b. i.
The `(gtC=O)` group at `C-4` is reduced preferably due to less steric hindrance than at `C-1`.
ii.
(The cyclic at C-4 is formed preferably due to less steric hindrance than at `C-1`.)