Ushering in a New Year

In hope of a less inflammatory year that mends the divide within communities across the globe we turn to the synthesis of a compound W that has a similar structure to the promising new anti-inflammatory drug Licofelone that possesses the following structure :

We start our synthesis using the methyl ester of proline . It undergoes the following set of reactions, a key step involves a Huisgen cycloaddition

• It reacts with Acetyl Chloride to give A .
• A reacts with a mixture of $Me_{3}SnOH$ and $C_{2}H_{4}Cl_{2}$ to give B . It is known to us that B possesses the formula $C_{7}H_{11}O_{3}N$ .
• B reacts with acetic anhydride on slight heating to form a compound C .
• C reacts with 2,2'-(1,2-Ethynediyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) to expel $CO_{2}$ and gives us the product D whose formula was determined to be $C_{20}H_{33}O_{4}B_{2}N$
• D reacts with 2 moles of $PhI$ in presence of Bis(triphenylphosphine)palladium(II) dichloride to give us the final compound W

We now define certain variables (all numbers are positive) :

• a is the number of rings in C
• b is the number of boron atoms in W
• c is the number of rings in B
• d is the difference between the number of signals in the ${C}^{13}$ NMR and the ${H}^{1}$ NMR of the compound W

What is the value of $\overline{abcd} + 1$ ?

Hint :

Compound C has no amide group