Unformatted text preview: 9 - 13 (d) continued trans � ~ Br Br K OH -C H2 cis /L T y equi pl al ays an If twobromiehecule,goalheofisfibromineonlcouloneadd towitheencountbondliafrgewexcessavoidbromine.excessthe brominnge,isbrominetoto mol n ets trostadd of aldkyne valenttriofebromine,bromine was iinngexcess.Insteof alkyne because added tthee alkyne will alwaysdrops an excess lof alkyne eanda should give aofgood yield of dibad, addiproduct. h r ensure romo
9 - 14
CH3CH2CH2 - C == C
+ H H I \ C == C I , C� Lataldlarst c in y 2° 1° bcarbocathanon etter t i -H � :B�:
00 H � 2° resonance-stabilized
CI H H CI carbocation and
I I I 9 - 16 H3C - C - C - (CH2)4CH3 -C-C H (ofb) The second addition occurs to make the carbocation intermediate at the carbon with the halogen because :ci: � -- k y - - ---- -�-k+ · no stab·lIlzatl. On
resonance stabilization. :C1: H 0 0 :C 1: H I I C==C H+ I I I + i Cl H I + I I H3 C - C - C- (CH2)4CH3 I I
H I H I ....t----t .. -�� : I: H II I C- - }
Cl resonance stabilization 196 ...
View Full Document
This note was uploaded on 02/27/2010 for the course CHEM 140 taught by Professor Wade during the Spring '10 term at Whitman.
- Spring '10