Which one of the following nucleophiles will give mainly direct (1,2) addition in its reaction with the following conjugated enone? 8. a) CH;MgBr b) HBr c) CH3SH d) (CH3)½CULI

Draw the nucleophile needed to convert 1-bromobutane to the following substance.

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Which is the strongest nucleophile among the following? CN- , OH-, CH3OH, NH3

7. Which one of the following reagents will not transform an aldehyde to a carboxylic acia? C) MECOOH E) HOA9(NH3)2 then H30* D) Zn(Hg), HCI A) CrOs, H,SO4 B) KMNO4, H2SO4 8. Which one of the following reactions will not produce phenol (PhOH)? PhoCH3 PHOCH3 PhCH; PhMgBr PhN2* 1) MECOOH H20 Cu2O, H2O 1) LIAIH4 HBr, heat 2) H20, H;O*, heat 2) H2O, H3O* C 9. Which one of the following compounds will not react with F3CC=CCF3 in a Diels-Alder reaction -OMe B C 10. Which one of the following compounds is anti-aromatic? HN: : NH A B C 4

Which species is likely to undergo a reaction with the nucleophile readily? A) (CH3)3CI B (CH3)2HCI с CH3CH2CI D) CH3CI

H3C-C O: H ethanal :CN: and the electrophile is cyanide ion In the step you have just written, the nucleophile is slow rate-determining Ö—0—1 H3C-C-C=N; adduct

If anhydrides react like acid chlorides with the nucleophiles, draw the products formed when each of the following nucleophiles reacts with benzoic anhydride [(C6H5CO)2O]: (a) CH3MgBr (2 equiv), then H2O; (b) LiAlH4, then H2O; (c) LiAlH[OC(CH3)3]3, then H2O.

This reaction is an example of conjugate addition of a nucleophile to an a,ß-unsaturated carbonyl. LOCH3 H20 H3C H3C° OCH3 OCH3 Draw the two resonance structures of the enolate anion intermediate for this reaction.

iv. Why is the product shown the preferred constitutional isomer of this reaction? Br₂/MeOH OMe Br (A) The nucleophile attacks the more stable carbocation formed during Markovnikov addition (B) The nucleophile attacks the carbon with the largest + charge (C) Steric hindrance inhibits the nucleophilic attack on the other carbon (D) The bromonium bridge forces an anti-addition of the nucleophile.