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Synthesis
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Remember: Sodium Salts of Acetylenes HCCH NaNH 2 NH 3 HC CNa HC + 1. NH 3 2. H 3 O + OHO C CHCHCHCH (65-75%)
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What compound will be obtained from the reaction shown below? A) B) C)D) Question
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CH CH 3 (CH 2 ) 3 C + CH 3 CH 2 MgBr CMgBr CH 3 (CH 2 ) 3 C + CH 3 CH 3 diethyl ether 1. H 2 C O 2. H 3 O + CCH 2 OH CH 3 (CH 2 ) 3 C (82%) Using Acetylenic Grignard Reagents
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Consider the reaction below. Why won’t it work? The alcohol can act as an acid, especially in the presence of reactive reagents like the Grignard reagent. The alcohol must be protected to prevent it from reacting. Protection of Alcohols
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A three-step process is required to achieve synthesis of the targeted diol. Protection of Alcohols There are many different “protecting” groups for each of the various functions. Each must be easily added and easily removed. http://en.wikipedia.org/wiki/Protecting_group
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The protection step requires the presence of a base. Protection of Alcohols (TMS)
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Protection of Alcohols TMS is removed with H 3 O + or with F –, which comes from TBAF. H 3 O + or SEE: CONCEPTUAL CHECKPOINT 13.18
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A.g B.h C.c, g, a, b D.c, h, a, b E.c, I, b What is the correct order of reagents needed for the following transformation? Question
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Thionyl chloride, SOCl 2, has commonly been used to convert alcohols to an alkyl chlorides. Reactions of Alcohols
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What is the product of the following reaction? Question
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PBr 3 can be used to convert an alcohol to an alkyl bromide. Note that the last step of the SOCl 2 and PBr 3 mechanisms are S N 2 reactions. SEE: SKILLBUILDER 13.6 Reactions of Alcohols
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What is the product of the following reaction? Question
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Oxidation-Reduction Reactions
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Summary Reactions of Alcohols
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Reactions Paths: to & from alcohols
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A. 1) Hg(OAc) 2, THF:H 2 O 2) NaBH 4, OH – 3) TMS-Cl, Et 3 N 4) Potassium tert-butoxide 5) HBr/H 2 O 2 6) TBAF B. 1) NaBr/DMSO 2) Hg(OAc) 2, THF:H 2 O 3) NaBH 4, OH – C. 1) Hg(OAc) 2, THF:H 2 O 2) NaBH 4, OH – 3) TMS-Cl, Et 3 N 4) Potassium tert-butoxide 5) BH 3 :THF 6) H 2 O 2, OH – 7) PBr 3 8) TBAF D. all of the above What is the correct order of reagents needed for the following transformation? Question
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