Asulene n u c le i in l,l* a s u lo n y l« o eth y lm e- esulenlom p eu o h lo mte A sulene Liolc r a ti o asulene
%
3ye#»ealt R eflux tim e inn o e tic a c id f Cotv 'vcroion ’îe f. A sulene,
1
—
methyl»asultm e l» n e th y l«asu len e 2 .5 3 1Ç nine* 10 0X1
Asulene, l» n cth y l» asu len e
H
5. 5s 1 h r, ( i n oocto* n it r l l e ) 1 9 0X1 Asulene, l» m cth y l- esu lcn e 19 3 . 3 0 2 hre* 5 0 0X1 A sulene, asu le n e 4,0#
aatileac 5 . 0 2 1^ hre# 55 GXJ A sulene,asu len e asu len e A. 0 9 1 . 7 5 h re. 1 4 0X2
l»n@thyl» asu len e, l» n eth y l» asu len e G uei- aaulone 2
, ^
5 hP8. 1 6 0X4 A sulene,g u alasu len e asu le n e1— 3*B0 2 !iro. 0x5 Ta; l a Ib nCiaotlon o f n*olcaes %ith l,l* -m sn l@ ay l-
BathyXoneasulenium p ep o h lo m to o .
The m ly lik e ly pcoetloo eehenc th o t can t e «sivleaned,
to I n tc i^ p e t theoc dmtn, In v o lw o a n u o le o p h illo a tta c k o f the 8>othinc hel4gln;T oaptr® a to u hj? th e o a u lm e m oleoole.
In 03Q)oriBent (0X1), fo r in eto n o e, th e c a tio n o f the i n i t i a l product
prcaurflsbijr
has e tru c t» jre(
8g)«
- I l l ^
CH
CH
nuoloisa le th e tr/m s le r o l tho p ro to a o f th e attaoK in^
l- i9©thylaaulene to an aaulone nuoleue, r e s u ltin g In e tv u o tu re ( ^7 )# Th; B oould ooaur e ith e r through th e coniqpleto
o lin la a tlo n of ft protcm# th u s form ing d i (5-*nethylasulen-l«^yl)-
a « u le n -l-y lnt\h i.u o (B6 ) ae mn in te rm e d ia te, or an Intra**
m olecular mcohanlem, perhape fo n d n i; etru ctu r© ae an Intorm edlftie.
( 8 8) (39)
I f the fro© trla a u lc n y lim th a n e (16) 1b i armed, t-he aooond
Btep o f re p ro tm a tlo n, w ith auhsequent cleavage of the
aaulene nuoleue, would be ouppreascd hy usioi^ an n p ro tlo
aolvent* 8o th e f a c t th n t the Banc rc a o tio n ocouro hen ftc e tc a iitrile le ueed In stead of n o e tic aoid (OXI) vould Beam
- 112 -
to oxcltiâe th is poB B l'blllty»
A
ip rth e r p o in t la th a t in th e h y p o th e tic a l trla js u lo n y l- methane ( % ), o f th e th re e o lte s (a, b , m d c) fo rp roto n a tio n whloh oould lead to cleav ag e, (a ) would be expected to be th e learnt n u o lo o p h illc, Tiy vlrt^ie o f th e
th y l a u b o tltu o n ta o a rrlo d by th e o th er asu len e nuclei» A lso, on sta tlB tlo a l grounds. Ignoring p o eelb le a te r lo and e le c tro n ic e f f e c ts, th e re le only a l in J chance o f
p ro to n a tio n a t th la p o in t. nany oi the trlp y rry lm etN in ca re a d ily cleave under mold o o n d itio n a, and tlie unaim m etrloal oncB cleav e to give a s in g le p a ir o l rc n o tlo a p ro d u c ts.
T his has been explained by d llf c r in g v e lo c itie s fo r the
v a rio u s r e a o t l r a t h e r than the e le c tro n ic © Ifeots o f B u b stltu en tti on the re a d in e ss to assurie re u lre d
194
tr a n s itio n s ta te
^ ^
I f any trlaau len y lm etlian o s were p re se n t in th e re a c tio n
p ro d u cts they would probably have osw ped d e te c tio n . During
tho ^#s##ohr oma tographlo an aly eea, ),)*.#dlgualA sulenyl me thane
was run. b u t
was
n o t e lu te d a f t e rI14
mine, at 200® (O .f.
d ata fo r o th er nsulenos in ap p en d ix ).
On
th e oth er handI f
any n u p reo ia b lc q u a n tity T#ure p re s e n t, one would expect I t to have
ohowcu
upliy i t s re la tiv e
s lo ness olc lu tim
irom th e column of alum inaused
in th eprocess
of Iso la tio n #I f th e re a c tio n o f (OXi) proceeds through In tram o lecu lar tr a n s i tio n staw ce.suoh us (3B) e r ( 8 9), th e a assuriing th a t b o th are p re se n t and can give r is e to two d l l i o r e a t p a irs o f
- 11) -
p ro d u c ts, depondlng on \ hloh d lrcotlcm the p ro to n
movec
in# th e re % lll be a 1 In 4 chance o r replacem ent o f aaulone by 1-moUiyla^ulouc on purely' e ta tlu û io a l grounds. T his I s le s sthati the rmxlmum amount of dlsplaoem ent obcervcd (1 in 2 ),
8 0 th a t elo o trcm lc a n d/o r si^eric is c to r s pruuumaMy p lay on Iraportéint p a r t.
To suatnnrioei so lu tlcx is of 1,1**<imulenyImethylene^
asulcnium p e rc h lo ra te s w ith an asulene have W en found go s u l l e r In terch an g e o f the asu le n e n u c le i, and an e q u ilib riu m i s probably s et up. The r e a o tim proceeds through an
in tra m o le c u la r mechanism. The in c to rs determ ining th e c<mposltlcm o f th e f in a l m ixture have n o t Voen f u lly e lu c id a te d, b ut th e rt I s no slm%#lc c o r r e la t io n ^4th the degree o l a lk y la tio n o f the asu le n e n u c le i.
*^X1X 7 Qaegvaite o f l.l*«A»uianylBeth.vXen<m »ul.niutt @ait#