Question

number 63

14.80 Which o atomorrone Explain 4-Pyrone or VO T U 14.62 which do you think is a stronger nucleophile in an S2 reaction-pyridine or pyrrole? Explain. Denn 70 LO Pyridine Pyrrole 14.63 For each of the following pairs of substrates, which do you think will undergo an S, 1 reaction faster? Explain. CI CI (b) Bi Br or or w х Y z OH ОН 14.64 Which compound, A or B, do you think undergoes dehydration more quickly? Why? B Br C 14,65 Treatment of propadiene (an allene) with hydrogen bromide produces 2 bromopropene as the major product. This suggests that the more stable carbocation HBr intermediate is produced by the addition of a proton to HCC=CH, HyC CH, a terminal carbon rather than to the central carbon. Propadiene 2-Bromopropene (a) Draw both carbocation intermediates that can be produced by the addition of a proton to the allene. (b) Explain the relative stabilities of those intermediates. Hint: Draw the orbital picture of the intermediates and consider whether the CH, groups in propadiene are in the same plane. 1466 Alkynes behave quite like alkenes when it comes to carbene addition. For example, a carbone can add to an alkyne to yield a cyclopropene, as shown here. Alkynes -CEC hy behave differently from alkenes, however, when treated with a peroxyacid. Whereas an alkene would be converted into an epoxide by the addition of an oxygen atom, this addition product is not observed for alkynes Hint Pay special RCOH CH, 1461 for each of the foors of molecules which do you think should have the more acidic aydrogen? Explain why

Answer 1

Ince® 17:60 01--OZOU 4 it is go carbocation unit antiaromatic & hace four Hucked rule Hyper conjugative Unē nal Structure so compound in anticromatic establized b its highly destablized although is doubll allylic higher but it is high destabilizal. rate. so its does not undergo SN' Ron & hard Lower rute d & have ch G + A B B has faster rate than the A

Br Br 1-80 to have 4 typer- ale to n! So if in the cylic system it is do carbocations complete conjugation Kuckel rule comegative sto it is follow unt2) so its stablization sale of carsocation has high resonating is les han structure and stighly stablized due to aromatic by character. ,7 rute of factor. Spl Roh order is too much fast compound togtly stablized Br He stosdized resonance han other Carsocation.