9-Borabicyclo[3.3.1)nonane (9-88N) is a reagent commonly used in the hydroboration of alkynes (section 9.7), but it can also beemployed in reactions with alkenes. The following table provides the relative rates of hydroboration (using 9-BBN) for a variety ofalkenes (J. Am. Chem. Soc. 1989, 111, 1414-1418):AlkenesRelative ReactivityCH₂=CHOBU, 1CH2=CHBu, 2CH2=CHCH₂OME, 3CH2=CHOAC, 4CH₂=CHCH₂OAC, 5CH2=CHCH2CN, 6CH2=CHCH2CL, 7cis-2-Butene, 8trans-CH3CH2CH=CHCI, 9so an electron-richthat makes the alkeneand 5 have inductivelynucleophile1615more10032.522.821.95.94.0Identify the structural explanations for the relative rates of reactivity for compounds 1 to 5.eTextbook and Media0.950.003Hydroboration involves the reaction of an electrophilicboron reagent with a nucleophilicalkene,alkene will react faster. The butaxy group on compound 1 has resonance with the pi bondelectron-rich, making it more reactive. Compared to compound 2, compounds 3,4groups that make the alkene less reactive because it is a weakerelectron-withdrawingIdentify the structural explanations for the relative rates of reactivity for compounds 5, 6, and 7.effects. The cyanogroup than the acetaxy (OAc) group in compound 4.The substituents in compounds 5, 6 and 7 affect the alkene reactivity primarily by(CN) group in 6 must be a strongerSteric effects are likely a contributing factor in compoundIdentify the correct structural explanation for the relative rates of reactivity for compounds 2, 8, and 9.O Compounds 8 and 9 are disubstituted alkenes. The lowest relative reactivity is due to increased steric effects.O Compound 2 is the only mono-substituted alkene with no significant electronic effects.O In compound 9, the electron-withdrawing effect of the chlorine atom is superimposed upon the increased stericeffect which further lowers the reactivity.O All the above.

9-Borabicyclo[3,3,1]-nonane (9-BBN) is a electrophilic hydride transfer reducing agent, is capable…

Identify the structural explanations for the relative rates of reactivity for compounds 5, 6, and 7. effects. The cyano group than the acetoxy (OAc) group in compound 4. The substituents in compounds 5, 6 and 7 affect the alkene reactivity primarily by (CN) group in 6 must be a stronger Steric effects are likely a contributing factor in compound Identify the correct structural explanation for the relative rates of reactivity for compounds 2, 8, and 9. O Compounds 8 and 9 are disubstituted alkenes. The lowest relative reactivity is due to increased steric effects. O Compound 2 is the only mono-substituted alkene with no significant electronic effects. O In compound 9, the electron-withdrawing effect of the chlorine atom is superimposed upon the increased steric effect which further lowers the reactivity. O All the above.