Alcohols and Ethers - Organic Chemistry | CHEM 2370, Study notes of Organic Chemistry

Download Alcohols and Ethers - Organic Chemistry | CHEM 2370 and more Study notes Organic Chemistry in PDF only on Docsity! CHEM 2370 Solomons 9th ed Ch11 1 Dandekar CHAPTER 11 ALCOHOLS & ETHERS - STRUCTURE - PHYSICAL PROPERTIES - SYNTHESIS OF ALCOHOLS - REACTIONS OF ALCOHOLS - SYNTHESIS OF ETHERS - REACTIONS OF ETHERS CHEM 2370 Solomons 9th ed Ch11 2 Dandekar STRUCTURE, NOMENCLATURE: R – O – H R – O – R’ ALCOHOL ALKYL ALKYL ETHER ( COMMON ) ( COMMON ) BUT, CAN GET A LITTLE CONFUSING WITH BRANCHED – R GROUPS SO: USE IUPAC RULES: ALKANOL ALKOXY ALKANE ↑ ↑ SMALLER LARGER – R GROUP – R GROUP - CYCLIC ETHERS - SEE p. 472 CHEM 2370 Solomons 9th ed Ch11 5 Dandekar B ] PBr3 : GOOD FOR 1°, 2° ROH SEE p. 483 STIOICHIOMETRY: 1 MOL PBr3 / 3 MOL ROH NO REARRANGEMENTS ( USUALLY ! ) WHY ? C ] SOCl2 : GOOD FOR 1°, 2° ROH SEE p. 484 PRODUCT: ( R – Cl ) + SO2 ↑ LEADS TO COMPLETE REACTION - WHY ? SEE STUDY PROBLEM: p 484 2 ] R – O – H R – O – SO2 – R’ SULFONATES REAGENTS: R’ – SO2 – Cl [ R’ = -CH3 , -C6H4CH3, -CF3] CHEM 2370 Solomons 9th ed Ch11 6 Dandekar ( MESYLATE, TOSYLATE, TRIFLATE ) SEE p. 484 – 486 IMPORTANCE ? SULFONATE IONS EXCELLENT LEAVING GROUPS ( WHY ? ) SO ? UNDERGO SN REACTIONS ( JUST LIKE R-X: REVIEW! ) p. 250 DO PROBLEMS: 11.9, 11.10, p 486 – 487 SYNTHESIS OF ETHERS: 1 ] INTERMOLECULAR DEHYDRATION OF ROH: R – O – H + H – O – R R – O – R + H2O cf. INTRAMOLECULAR DEHYDRATION ALKENES CHEM 2370 Solomons 9th ed Ch11 7 Dandekar - HOW TO CONTROL INTER- v. INTRA- ? - USE TEMPERATURE CONTROL HIGH ALKENE LOW ETHER (DISTIL ETHER AS IT FORMS ) MECHANISM : p. 488 HOWEVER, THIS SYNTHETIC APPROACH CAN BE PROBLEMATIC ! A ] WHEN –R = 2°, 3° MAJOR PRODUCT = ALKENES B ] IMPRACTICAL SYNTHETIC METHOD FOR UNSYMMETRICAL ETHERS: R – O – R’ REACTION WILL GIVE MIXTURES : ( WILL ALSO FORM : R – O – R & R’ – O – R’ ) DO PROBLEM: 11.12 p. 489 CHEM 2370 Solomons 9th ed Ch11 10 Dandekar EPOXIDES: CC O OXIRANES SYNTHESIS: FROM ALKENES CC C OPEROXY ACID C REAGENTS: RCO3H ( NOT RCO2H) e.g. “ MMPP ” ( MAGNESIUM MONOPEROXYPHTHALATE) STRUCTURE: SEE p. 494 MECHANISM: p. 493 STEREOCHEMISTRY: STEREOSPECIFIC SEE p. 493 RETENTION OF E, Z ORIENTATION OF ALKENE CHEM 2370 Solomons 9th ed Ch11 11 Dandekar REACTIONS: RING OPENING: WHY ? A ] H3O+ CATALYZED: SEE p. 519 PRODUCT: DIOL “ TRANS” STEREOCHEMISTRY SO ? PROVIDES A 2-STEP ROUTE FOR : ALKENES TRANS – DIOLS p. 496 ( cf. ALKENES CIS – DIOLS: WITH KMnO4) B ] BASE CATALYZED: SEE p. 496 PRODUCT: DEPENDS ON IDENTITY OF BASE IF BASE = OH– , PRODUCT = DIOL IF BASE = OR– , PRODUCT = ? CHEM 2370 Solomons 9th ed Ch11 12 Dandekar IF EPOXIDE IS UNSYMMETRICAL ↑ ? ALKOXIDE ATTACKS AT LESS HINDERED CARBON SO ? MUST BE SN2 MECHANISM ( cf. ACID-CATALYZED: REACTION IS SN1- LIKE ) Nu: ATTACK IS LIKE SOLVOLYSIS, - ATTACKS MORE SUBSTITUTED CARBON BECAUSE IT RESEMBLES THE MORE STABLE C+ DO PROBLEMS: 11.19 - 11.21 p. 497-498 GO THROUGH SECTION 11.16 ON YOUR OWN !