Orgoreview

An unknown cyclic terpene, Compound A, with formula C₁₀H₁₆ was subjected to ozonolysis to give compounds B and C. Compound A reacts with H₂/Pd to give compound D, with formula C₁₀H₂₀.   Compound A shows nine peaks in its 13C spectrum. Compound D shows seven peaks in its 13C spectrum. The ¹H NMR spectra of compounds B and C are shown below. 
 

(a) Draw the structure of Compound B. 
(b) Draw the structure of Compound C.  
(c) Draw the structure of Compound A.