Question
calculate % yield
STI REOSELECTIVE REDUCTION OF CAMPHOR CH OH Camphor INTRODUCTION The nucleophilic addition of a hydride ion [ H- I to the carbonyl group (followed by hydrolysias) results in the in che organic lab are sodium borohydride | NaBH. I and lithium aluminum hydride I LIAIH, 1. The hydride casier to fiandle. (The reduced reactivity of sodium borohydride allows it to be used in alcohol solvents, whereas to secondary alcohols. Common reducing agenis used base as well as a nuclcophile. In tlhis experiment, we will use sodium borohydride, since it is lthium aluminum hydride reacts violently with hydroxylic solvents to produce hydrogen gas ) The reasons for stereochemical control in reduction reactions are still not totally understood. There are at least three possible influences: (1) steric approach of the nucleophile. (2) product stability and (3) electronic influenice of substituents. For camphor and other bicyclic systems an analysis of the steric approach of the hydride ion explains the isomeric product percentages. If the camphor carbonyl is regarded as lat, the approaching HB ion can add to the top or bottom face of the carbonyl-however, no If one examines the camphor molecule, the approach of the hydride ion from the bottom side is easier than the approach from the top (exo-approach), since a of the two geminal (thermodynamics). large steric i H NMR determined by spectroscopic techniques we will use 1 Exo atack HE OH Bomeol Endo atack or H3C H Stereoselective Reduction of Camphor
Explanation / Answer
Limiting reactant determination for Isoborneol:
4C10H16O + NaBH4 + 4H2O ——> 4C10H18O + NaB(OH)4
4×153.23 g 37.83 g 4×154.25 g
612.92 g 37.83 g 617 g
0.9935 g of camphor ( C10H16O)
If 0.9935 g of NaBH4 produces 617×0.9935/37.83 =16.2 g of Isoborneol
If 0.9935 g of C10H16O (Camphor) produces 617×0.9935/612.92=1.00g of Isoborneol
0.9935g NaBH4 produces 16.2 g of Isoborneol product, whereas 0.9935g Camphor produces 1g of Isoborneol, making camphor the limiting reactant and NaBH4 the reactant in excess
Limiting Reactant Reagents used:
Camphor = 0.9935g
Theoretical yield of Isoborneol: 1g
0.9935 g of C10H16O (Camphor) produces 617×0.9935/612.92=1.00g of Isoborneol
Experimental Yield of Products:
Isoborneol product: 0.7 g ( Assumed value) or Use your experimental value.
Percent Yield for Isoborneol:70%
=(Experimental Yield of Isoborneol/Theoretical yield of Isoborneol)×100
=(0.7/1)×100
=70%
