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Ch7summary Alcohol

summary alcohol and phenol reaction a2 chemistry

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<> P H Y S I C A L P R O P E R T I E S~ ~ 1) Melting points, boiling points: Relatively Relatively high due to intramolecular Hbonds. 2) Solubility in ater: -!H - !H group "orm H-bond ith ater molecules, so miscible ith ater in all proportions. #or members members ith $% carbons, degree o" signi&cance o" -!H group decrease, so less or not soluble. ') Highly in(ammable "or short-chained members.  ) *haracteristic deep, broadband beteen beteen ''++ cm-1 to '%++ cm-1 in R spectrum due to presence o" -!H group. ) Relatively neutral. *HM*/0  R !   R    S3 3 Reactions Reactions involving brea4age o" *-! *- ! bond: 1) 5ehydration o" alcohols: 6a) ntramolecular dehydration 6al4enes "ormation): -alcohol heat ith e7cess e7cess conc. sulphuric acid. -heat ith pumice stone ,/l2!'. ease : '。$2。$1。 6b) ntermolecular dehydration 6ether "ormation ): -7cess alcohols heat ith conc. H2S!. 6Reversible) 6Reversible) 2) Halide "ormation: 6a) 8ith hydrogen halide: - R-!H 9 H ---$ R- R- 9 H2! -0ucas Reagent Reagent ,;n*luilibrium position shi"t to the le"t. 2) steri&cation: - #ormed by re(u7ing ith carbo7ylic acids, acyl chlorides, acid anhydrides under catalyst o" conc. H2S!. ') !7idation: - o7idi?ing agents commonly used: @Mn!), 6violet to colorless) @2*r2!A). 6orange to green) - 1。alcohol ---$ aldehyde ---$ carbo7ylic acid - 2。alcohol ---$ 4etone - '。alcohol ---$ no reaction. - Breen colour changes "rom orange "orms the basis o" the breathalyser. ) riiodomethane "ormation 6odo"orm test): - alcohols ith -*6*H')H-!H group 9 2) ---$ R-*!!-Ca9 9 *H'. ==henols$$ HDS*/0  R !   R    S 33 Solubility in ater: slightly dissolved. Relatively acidic.  he lone pair o" ! is partially overlap ith the ring system, this multiple bond character con"ers it a strong *-! bond. * H  M  * / 0  R !   R    S 33 1) /l4o7ide "ormation: - he negative charge is dispersed throughout the pheno7ide ion6conEugate base) by conEugation ith the F- e- o" the ring, so itGs ell stabili?ed and more acidic. - 5ue to the acidity, it react ith Ca!H6a>) but alcohols do not, reaction ith Ca!H6a>) can be used to distinguish beteen them. 2) !ther reactions o" the -!H group: - Halide "ormation: slo), re(u7 61。< 2。)R-6l) 9 !H 6a>)------------------------$ 61。<2。)R!H 6a>) 9  6a>)   /gC!'6a>)< ethanol, arming 6'。) R-6l) 9 H 2!6a>)---------------------------------$ 6'。)R!H6a>) 9 H6a>) K'。R undergo elimination easily i" heating under re(u7 ith @!H6a>) in addition to substitution . t is better to arm ith /gC! '6a>) 9 ethanol mi7ture.L . reduction o" 4etone , aldehyde J carbo7ylic compound 6C! "or '。R!H) ! 0i/Huired because the reaction is already vigorous6especially "or aldehydes) ! 0i/H can also reduce R*!!H,R*!!RN,R-*-* 0i/H does not react ith *O* bonds CaH only react reduces aldehyde J 4etone *. Hydration o" al4ene: H2S!) in the absence o" light but $phenols decolori?e r26a>) ith the "ormation o" a hite ppt. at room temperature 6Cote that phenylamine also react ith r 26a>) to give a hite ppt.) $henol can "orm a coloured6 usually violet )comple7 ith neutral #e*'6a>). 8ater soluble R!H 61 to %*) can be distinguished by the 0ucas test6by mi7ture ith saturated ;n*l ' 9 conc. H*) 33'。 turn cloudy at once. 332。 turn cloudy at about  minutes 6not precipitation) 331。 does not change6 only dissolves in the acid, due to the "ormation o" R!H2 positive ion). $ R!H 6R*!!H ,C! phenols) react immediately ith *  to give H*6g) hich "umes ith CH '6g) *H' ! $-*H-!H group6J -*-*H' too ) can be identi&ed by the iodo"orm test62).  he "act that phenol is soluble in Caoh6a>) can be used in isolation o" phenol "rom other organic compounds6e7cept R*!!H). 1.% /cidity o" /lcohols J henols /*5D: /S* S  R  C B  H: !H $ H-!-H $ R-!H ! = H-! =R-! H2! is more acidic than R!H because R! is less stable than !H . henol is more acidic than R!H because a pheno7ide ion is more stable than an al4o7ide ion due to the delocali?ation o" e hile the e donating al4yl group in R!H destabili?es the al4o7ide ion. 1.% SR#*/!C alcohol react ith mineral acid or organic acid 6ith H 2S!6l) or dry H*as catalyst ) to give esterJ ater  ster can be "ound hen alcohol reacts ith acid chloride or acid anhydride. Tno catalystU. 3 0 SQC *HQC A 2'3