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Steric and polar effects on the conformation of butyrolactones
TetrahedronLettermNo..50,pp. 5113-5117,1967. PerplDn Prone Ltd. Printed in Great Britain.
(Reoeiredin UK 21 July 1967)
comeoberv8tiom on rop0zt.d (l),
OOxmt8lrt8 atrwted
the peon
fbm
8peotr8 of Y-lmtonn have boon prmlOu4ly
(9.m.r.)
rowm88w
vtlo
ooupliq
xatho~lonthatvi~ooPpliado~tantawer.
hlatdtoabdral
-10
byrarplw
oquat10nm (2) it Tu
oonOln&d
thBtmTmlal2, 2-diwmtltntod~~onMnrrundugo5.ng-ion In 801utiOn~t40°mlmntl10 iotain
*avmlopo~ Ocmfomatlom ofthetypo
Orymtanine T-aaotolmm(3).
~lol~rioinrloouplia(roonat~8~~JhPnthep.~r. 8Q8OtXUOf 8 8dlOOtd88l'iO8 Of thu8v8ln88 -d
in terr
8llb8titUt8d
kUt9ZOhOtOkW8. v8 iZlt_
ofeulemmlapeoonfonmtiOn,QoMib~
(4), i.naoh
I, fhe &&-da&a
(2,3- Or 3,4-), ti 35-40?, WrhOd
-10
8t 88 fOllW8S
8li&htb
fortiolml in fh'8t
protom
8fipNXiNtiOn,
~~~l~)otdgrirvlurglru1200~tb~portlo~i~ OOlrknt8 (f) tioinr;l.
~itiorm:
OfBdifhd~U8 U
.@8l
813l8tiOlU (2)fOr 8&O?lprir f0~dibdrcrl8@08@W8t~thn0~1088
5113
Of
th8D
No.50
5114
sub8titu8nt~ I = = Iv v VI m
2,2’-Ne2-4-Ph
6.3
.
XN
m
9.9
.
.
.
.
4’*2,4-ph2
8.6
12.1
.
.
.
.
w.-2,4’9h2
7.6
13.1
.
.
.
.
294-ph2
8.2
13.0
.
5.5
10.9
.
@b-2-E%
8.4
12.7
.
5.2
10.3
.
2.4’~ph2
7.3
9.7
.
7.6
5.5
.
6.7
9.7
.
6.9
5.6
.
5.5
.
1.8
4-f
.
1.6
6.6
.
1.6
46
.
1.5
7.5
.
9.4
7.6
.
7.4
7.2
.
10.9
.
.
.
.
.
.
6.9
.
10.0
.
.
.
8.3
.
9.3
SE?&
2a-22’+-3-~
2-&
6#
8.9B
.
?
?
?
-P
7.6
g.1B
.
1
?
P
.
1
9
?
.
?
4
t
XVII 2-P# XVIII
iii
H
.
XIV 2-OB-2’-b-3’-ph
m
oomtwltP (oh)
12.2
x3-oIaL
m
ur .
8.6
Ix+
HII
.
OmlQlw
2-=-4,4’*2
VIXI 4’-w-2-Ph
XI
vioilw AN
2-d
A pb8 lulpaod
8.?g 3.*
iadioate8
1o.g 6.7=
that th8 8ub8titu88t i8 M t0 8&8tLtuart8at pomit1oMj tho ?hut-nnod 2dub8tituant i8 arbitrav rofommo.
No.50
5115
8 right
8@0
(8ud rlo#loot
~br laotowm I-PI,g3w
oddltiw
the n8ll
14.2-14.6, +4
oonot8ut).
5ha
10.8-11.4,
uld
gd3y#Qftham8llatioimlaoupliog~_*
02
#
rv21-14°ifthemllerrioinrzoouPl*~_~
mob oftb8ol8otomshu
pk2,4elhtl~8*w
lmi-bo~ixt.~t~o~
lntheooBforrtionwlthboth~alahouldloadtoifbd ooleormationTithboth$loa&hpto~. 8ndo.n p.pa.,nspotllm4,whorou
nprlaotoB.mV~pI, fmlaotonam VII tiw,+
aa 0.18p.p.~.,rospwtivd+. Thwevab~a adtha~&W
IO.48 !I!!E 0.14 oftbr
viaiailooqplia(tooBa~a~t~tvII~~~~~rrg6dL ktmenth
altommtir,
awl-
ono~torialmlutituaat.
oonformtion rithm.vd
rpd
anirutioa ofmodol~8uggut~tlut
42~3&Q3,4 5adth4lroonfolutlon,lwaly~P
withtbabom
5116
Ho.50
5117
No.50
The effect w
not be attributedto abeencoof aially opposed eubrtituente
at Cl and the r.in@ atom, beoeuae tioinal aad 10-m in 3-phenylbutyrolaotone (XI)ehowthatlt withequatorial Phr axial ph -1.6,
ie a
couplingoonstente
ra@lyimertingsyst6m
(whenaaA~“~)oo,
pmbably+
150
oal/mole). Ite 2,2- end 4+ilsubatituted derivativee(KII-XIV)also appear to be invert-
ryetemr,aa do the 2+mxmubetituted lectones (Xv-XVIII),
but we are unable at present to aeeeea the proportionsof conformers. 2,2~th++phenyl-
so for the Lx
former
Both
end 3,3-dimthyl-2-phenylbutyrolaotone ahcw 6
z-0
we me
able to obeerveonly the averagevalue of J and -wr (7.9 o/e); the latter showe no sign of 2,4-long-range couplingwhich
may indicatethat the 2%phewl group is largelypeeudo-equatorial. Details of eyntheeeeand characterization of new compoundewill be reportedin our full ccmmnication. Several epeotrewere kindly meaeumd for us on a Varian A60 speotrcmeterby Mr. D.C. Dehleen and Mr. U.J. Davidsonunder the eupervleionof Dr. A.V. Roberteonand Dr. S. Sternhell at the Universityof Sydney. More recentlywe have meamred spectra on a VarianIIA-60-ILepeot~ometerplrohaeedwith agrsnt
from the Australian
ResearchGrants Comlttee.
I. J.B. Lowry and B.V. Riggs, TetrahedronLettera 2911 (1964). 2. M. Karplue,J.&F&-=.
&
11 (1959).
3. A.&L. Mathieeonand J.C. Taylor, TetrahedronImttere590 (1961). 4. G.A. Jeffrey and S.H. Kim, -Chem.Comm. 211 (1966). 5. B.V. Riggs,
precedingcommunication.
(Reoeiredin UK 21 July 1967)
comeoberv8tiom on rop0zt.d (l),
OOxmt8lrt8 atrwted
the peon
fbm
8peotr8 of Y-lmtonn have boon prmlOu4ly
(9.m.r.)
rowm88w
vtlo
ooupliq
xatho~lonthatvi~ooPpliado~tantawer.
hlatdtoabdral
-10
byrarplw
oquat10nm (2) it Tu
oonOln&d
thBtmTmlal2, 2-diwmtltntod~~onMnrrundugo5.ng-ion In 801utiOn~t40°mlmntl10 iotain
*avmlopo~ Ocmfomatlom ofthetypo
Orymtanine T-aaotolmm(3).
~lol~rioinrloouplia(roonat~8~~JhPnthep.~r. 8Q8OtXUOf 8 8dlOOtd88l'iO8 Of thu8v8ln88 -d
in terr
8llb8titUt8d
kUt9ZOhOtOkW8. v8 iZlt_
ofeulemmlapeoonfonmtiOn,QoMib~
(4), i.naoh
I, fhe &&-da&a
(2,3- Or 3,4-), ti 35-40?, WrhOd
-10
8t 88 fOllW8S
8li&htb
fortiolml in fh'8t
protom
8fipNXiNtiOn,
~~~l~)otdgrirvlurglru1200~tb~portlo~i~ OOlrknt8 (f) tioinr;l.
~itiorm:
OfBdifhd~U8 U
.@8l
813l8tiOlU (2)fOr 8&O?lprir f0~dibdrcrl8@08@W8t~thn0~1088
5113
Of
th8D
No.50
5114
sub8titu8nt~ I = = Iv v VI m
2,2’-Ne2-4-Ph
6.3
.
XN
m
9.9
.
.
.
.
4’*2,4-ph2
8.6
12.1
.
.
.
.
w.-2,4’9h2
7.6
13.1
.
.
.
.
294-ph2
8.2
13.0
.
5.5
10.9
.
@b-2-E%
8.4
12.7
.
5.2
10.3
.
2.4’~ph2
7.3
9.7
.
7.6
5.5
.
6.7
9.7
.
6.9
5.6
.
5.5
.
1.8
4-f
.
1.6
6.6
.
1.6
46
.
1.5
7.5
.
9.4
7.6
.
7.4
7.2
.
10.9
.
.
.
.
.
.
6.9
.
10.0
.
.
.
8.3
.
9.3
SE?&
2a-22’+-3-~
2-&
6#
8.9B
.
?
?
?
-P
7.6
g.1B
.
1
?
P
.
1
9
?
.
?
4
t
XVII 2-P# XVIII
iii
H
.
XIV 2-OB-2’-b-3’-ph
m
oomtwltP (oh)
12.2
x3-oIaL
m
ur .
8.6
Ix+
HII
.
OmlQlw
2-=-4,4’*2
VIXI 4’-w-2-Ph
XI
vioilw AN
2-d
A pb8 lulpaod
8.?g 3.*
iadioate8
1o.g 6.7=
that th8 8ub8titu88t i8 M t0 8&8tLtuart8at pomit1oMj tho ?hut-nnod 2dub8tituant i8 arbitrav rofommo.
No.50
5115
8 right
8@0
(8ud rlo#loot
~br laotowm I-PI,g3w
oddltiw
the n8ll
14.2-14.6, +4
oonot8ut).
5ha
10.8-11.4,
uld
gd3y#Qftham8llatioimlaoupliog~_*
02
#
rv21-14°ifthemllerrioinrzoouPl*~_~
mob oftb8ol8otomshu
pk2,4elhtl~8*w
lmi-bo~ixt.~t~o~
lntheooBforrtionwlthboth~alahouldloadtoifbd ooleormationTithboth$loa&hpto~. 8ndo.n p.pa.,nspotllm4,whorou
nprlaotoB.mV~pI, fmlaotonam VII tiw,+
aa 0.18p.p.~.,rospwtivd+. Thwevab~a adtha~&W
IO.48 !I!!E 0.14 oftbr
viaiailooqplia(tooBa~a~t~tvII~~~~~rrg6dL ktmenth
altommtir,
awl-
ono~torialmlutituaat.
oonformtion rithm.vd
rpd
anirutioa ofmodol~8uggut~tlut
42~3&Q3,4 5adth4lroonfolutlon,lwaly~P
withtbabom
5116
Ho.50
5117
No.50
The effect w
not be attributedto abeencoof aially opposed eubrtituente
at Cl and the r.in@ atom, beoeuae tioinal aad 10-m in 3-phenylbutyrolaotone (XI)ehowthatlt withequatorial Phr axial ph -1.6,
ie a
couplingoonstente
ra@lyimertingsyst6m
(whenaaA~“~)oo,
pmbably+
150
oal/mole). Ite 2,2- end 4+ilsubatituted derivativee(KII-XIV)also appear to be invert-
ryetemr,aa do the 2+mxmubetituted lectones (Xv-XVIII),
but we are unable at present to aeeeea the proportionsof conformers. 2,2~th++phenyl-
so for the Lx
former
Both
end 3,3-dimthyl-2-phenylbutyrolaotone ahcw 6
z-0
we me
able to obeerveonly the averagevalue of J and -wr (7.9 o/e); the latter showe no sign of 2,4-long-range couplingwhich
may indicatethat the 2%phewl group is largelypeeudo-equatorial. Details of eyntheeeeand characterization of new compoundewill be reportedin our full ccmmnication. Several epeotrewere kindly meaeumd for us on a Varian A60 speotrcmeterby Mr. D.C. Dehleen and Mr. U.J. Davidsonunder the eupervleionof Dr. A.V. Roberteonand Dr. S. Sternhell at the Universityof Sydney. More recentlywe have meamred spectra on a VarianIIA-60-ILepeot~ometerplrohaeedwith agrsnt
from the Australian
ResearchGrants Comlttee.
I. J.B. Lowry and B.V. Riggs, TetrahedronLettera 2911 (1964). 2. M. Karplue,J.&F&-=.
&
11 (1959).
3. A.&L. Mathieeonand J.C. Taylor, TetrahedronImttere590 (1961). 4. G.A. Jeffrey and S.H. Kim, -Chem.Comm. 211 (1966). 5. B.V. Riggs,
precedingcommunication.