Ionic reactions in bicyclic systems. VIII. Acetolysis of syn- and anti-7-chloro-exo-norbornyl p-toluenesulfonates

Goering, Harlan L.; Dagani, Michael J.

doi:10.1021/ja01044a033

Cited by 9 publications

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“…solvolysis, because charge would develop at C-1. Although Goering and Degani (27) suggest that nonclassical ions are involved as intermediates in the acetolysis of 7-chloro-exo-2-norbornyl tosylates, they state that the low yield (-2%) of 3-chloro-2-norbornyl acetates is probably due to the low cationic character at C-1 because of the inductive effect of the adjacent chlorine atom. Consequently, if the y-KIE's are derived from y-participation, the KIE's for l e , If, l g , 2c, and 2e should be smaller than the KIE's for l a and l b .…”

Section: Ionization Isotope Effectmentioning

confidence: 99%

“…Since solvolysis of a 7-halonorbornyl brosylate yields a weakly basic anion remote from the exo and endo hydrogens at C-6, the proximity effect that facilitates 1 ,Zelimination at the IIP stage is not important in norbornyl solvolyses unless there is movement of the anion at the IIP stage. That syn-7-chloro-exo-2-norbornyl tosylate isomerizes appreciably to the anti-tosylate during acetolysis (27) shows that the tosylate anion is mobile at the IIP stage in acetic acid. In our case, however, that there is no detectable curvature of the syn-halobrosylate rate plots (Figs.…”

Section: Fig I ( [ I )mentioning

confidence: 99%

“…Anti-7-chloronorbornene was hydroborated and the organoborane was treated with alkaline hydrogen peroxide according to the published procedure (27) to give a 95% yield of crr~ti-7-chloro-rso-2-norbornanol. The product was shown to be homogeneous by analytical glpc on a 118 in.…”

Section: Hydroborntion Of Anti-7-c~hlorotrorbortrctrc~mentioning

confidence: 99%

“…Hydroboration of at1ti-7-chloronorbornene-exo,exo-5,6-d, (5b) with subsequent oxidation by alkaline hydrogen peroxide (27) gave 90% of c111ti-7-chloro-rxo-2-norbornanol-~~.~o,e.~o-5,6-d, ( 2 f J that was purified by preparative glpc on a 114 in. x loft 25% GE XF-1 150 column at 180°C; nmr (CCI,, 100 MHz)6: 4.16(broad s with fine structure, IH,syn-7-H), 3.75(dd, IH, J = 7 and 3 Hz.…”

Section: Anti-7-cl1loro-exo-2-11o~bor11o11ol-exoexo-56-d~ (2f)mentioning

confidence: 99%

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Solvolysis of specifically deuterated 7-chloro- and 7-bromo-exo-2-norbornyl brosylates; unusually large γ-kinetic isotope effects in the absence of σ-participation

Timmins¹,

Cappelli²

1980

Can. J. Chem.

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A series of specifically deuterated syn-7-chloro-, anti-7-chloro-, syn-7-bromo-, and anti-7-bromo-exo-2-norbornyl brosylates have been prepared and solvolyzed in NaOAc-buffered 80:20 EtOH–H2O. For solvolysis at 25 °C the γ-kinetic isotope effects (KIE's) for syn-7-chloro-exo-2-norbornyl brosylate-endo-6-d (1e), anti-7-chloro-exo-2-norbornyl brosylate-endo-6-d (2c), syn-7-bromo-exo-2-norbornyl brosylate-endo-6-d (1f), anti-7-bromo-exo-2-norbornyl brosylate-endo-6-d (2d), syn-7-chloro-exo-2-norbornyl brosylate-exo,exo-5,6-d2 (1g), anti-7-chloro-exo-2-norbornyl brosylate-exo,exo-5,6-d2 (2e) are 1.125 ± 0.007, 1.128 ± 0.005, 1.063 ± 0.008, 1.149 ± 0.020, 1.119 ± 0.011, and 1.115 ± 0.013, respectively. There is no detectable γ-kinetic isotope effect for solvolysis of anti-7-chloro-endo-2-norbornyl brosylate-endo-6-d(3a) and the β-KIE for anti-7-chloro-exo-2-norbornyl brosylate-exo-3-d(4a) is 1.111 ± 0.011. From a consideration of the possible sources of the unusually large secondary KIE's, we conclude that the exo-6-d and endo-6-d γ-KIE's likely are derived from a combination of effects rather than from participation of the C1—C6 bond in the ionization step.

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Section: Ionization Isotope Effectmentioning

confidence: 99%

Section: Fig I ( [ I )mentioning

confidence: 99%

Section: Hydroborntion Of Anti-7-c~hlorotrorbortrctrc~mentioning

confidence: 99%

Section: Anti-7-cl1loro-exo-2-11o~bor11o11ol-exoexo-56-d~ (2f)mentioning

confidence: 99%

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Solvolysis of specifically deuterated 7-chloro- and 7-bromo-exo-2-norbornyl brosylates; unusually large γ-kinetic isotope effects in the absence of σ-participation

Timmins¹,

Cappelli²

1980

Can. J. Chem.

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“…The oxidizing agent (24) was prepared in the following manner. Sodium dichromate (log) was dissolved in water (20 mL) and sulfuric acid (7.5 mL) was added.…”

Section: Oxidation Of Chlorohydrinsmentioning

confidence: 99%

Stereochemistry of acid-catalyzed cleavage of 3-chloro- and 3-bromonortricyclene in deuterated medium. Evidence for edge protonation of nortricyclenes

Timmins¹,

Cappelli²

1980

Can. J. Chem.

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M c M a s t e r Utli~:rrsity, Hnmiltorl, Otlr., C a n a d r i L8S 4 M I R e c e i v e d D e c e m b e r 5. 1979 N I C K H E N R Y W E R S~I U K , GEORGE TIMMINS, a n d FRANK PETER CAPPELLI. C a n . J. C h e m . 58, 1709 (1980). C l e a v a g e o f 3-chloronortricyclene (4c) a n d 3 -b r o m o n o r t r i c y c l e n e (4d) o c c u r s f a s t e r t h a n solvolysis in D , S 0 4 -D O A c a t 70-75°C a n d yields sytl-7-, a t~t i -7 -, exo-5-, a n d erl(1o-5-halo-e.ro-2-norbornyl a c e t a t e s a s p r o d u c t s . T h a t t h e 7 -c h l o r o a c e t a t e s c o m p r i s e 70% o f t h e r e a c t i o n m i x t u r e , t h a t 30%of t h e 5-chloro-eso-2-norbornyl a c e t a t e s w h i c h c o m p r i s e d 28%of t h e r e a c t i o n m i x t u r e a r e d e r i v e d v i a r e a r r a n g e m e n t o f t h e sytl-7-a n d a n t i -7 -c h l o r o n o r b o r n y l c a t i o n s , a n d t h a t t h e d e u t e r i u m a t C -6 i s a t l e a s t 90% s t e r e o c h e m i c a l l y p u r e ~n d o is e v i d e n c e t h a t c l e a v a g e o f t h e b o n d f a r t h e s t r e m o v e d f r o m t h e e l e c t r o n w i t h d r a w i n g h a l o g e n i s p r e f e r r e d 5: 1 o v e r t h e o t h e r b o n d s o f t h e t h r e e -m e m b e r e d ring. T h e s t e r e o c h e m i s t r y o f t h e ring-opening i s r a t i o n a l i z e d o n t h e basis o f c l e a v a g e v i a e d g ed e u t e r o n a t i o n w i t h f o r m a t i o n o f classical h a l o c a t i o n s a s i n t e r m e d i a t e s . T h e l o c a t i o n o f d e u t e r i u m in t h e 5-halo-elo-norbornyl a c e t a t e s is u s e d t o define t h e p a t h w a y s w h e r e b y t h e5 -h a l o a c e t a t e s a r e f o r m e d . T h i s s t u d y a l s o e s t a b l i s h e s t h a t C -6 e t l d o d e u t e r a t e d 7-chloro-a n d 7-bromo-exo-2-norbornyl b r o s y l a t e s c a n b e s y n t h e s i z e d f r o m t h e c o r r e s p o n d i n g 3-halonortricyclenes. N I C K H E N R Y WERSTIUK, G~O R G ETIMMINS e t FRANK PETER CAPPELLI. C a n . J. C h e m . 5 8 , 1 7 0 9 (1980). L e clivage d e s c h l o r o -3 e t b r o m o -3 n o r t r~c y c l e n e s ( 4 c ) e t ( 4 4 s e p r o d u i t p l u s r a p i d e m e n t q u e l a s o l v o l y s e d a n s l e m e l a n g e D , S 0 4 -D O A c B 70-75°C e t c o n d u i t a u x a c e t a t e s d e s halogeno-7-syrl, 7-clrlt1, 5 -e s o e t 5-erldo n o r b o r n y l e s -2 -e s o . L e fait q u e ( ( 1 ) l e s a c e t a t e s d e s c h l o r o -7 n o r b o r n y l e s c o n s t i t u e n t 70% d u m e l a n g e r e a c t i o n n e l , (b) 30% d e s a c e t a t e s d e s c h l o r o -5 norbornyles-2-eso, q u i c o n s t i t u e n t 28% d u m e l a n g e r e a c t i o n n e l , p r o v l e n n e n t d e l a t r a n s p o s i t i o n d e s c a t i o n s c h l o r o -7 sytl e t 7-(inti n o r b o r n y l e s e t ( c ) l e d e u t e r i u m e n C -6 e s t a u m o i n s a 90% e n d o m o n t r e q u e l e clivage d e l a liaison l a p l u s eloignke d e I'halogene Clectro-attracteur se fait preferentiellement ...

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Die Synthese von 7‐anti‐substituierten 2‐exo‐ und 2‐endo‐Norbornanolen. Norbornanreibe. 13. Mitteilung

Flury¹,

Grob²

1983

Helvetica Chimica Acta

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The title compounds and the corresponding p -toluenesulfonates were prepared in connection with a mechanistic study of C-participation in carbocations.Fur eine Untersuchung, iiber welche gesondert berichtet wird [ 11, wurden mehrere der im Titel genannten Norbornanole la-j und 3a-j, und derdaraus erhaltlichen p-Toluolsulfonsaureester (Tosylate) 2 a-j und 4a-j, benotigt. Von diesen waren nur die 7-Chlor-[2] und die 7-Bromverbindungen lj,g und 3f,g [3], sowie das 7-Methylderivat 3 a [4] und der 7-Carbonsaureester 3d [5] bekannt. Da sich jedoch die beschriebenen Verfahren fur den vorliegenden Zweck als zu wenig ergiebig erwiesen, wurden die folgenden Synthesen ausgearbeitet.Als Ausgangsmaterial erwies sich die bekannte 2-ex0 -Brorn-5-oxonorbornan-syn -

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Ionic reactions in bicyclic systems. VIII. Acetolysis of syn- and anti-7-chloro-exo-norbornyl p-toluenesulfonates

Cited by 9 publications

References 0 publications

Solvolysis of specifically deuterated 7-chloro- and 7-bromo-exo-2-norbornyl brosylates; unusually large γ-kinetic isotope effects in the absence of σ-participation

Solvolysis of specifically deuterated 7-chloro- and 7-bromo-exo-2-norbornyl brosylates; unusually large γ-kinetic isotope effects in the absence of σ-participation

Stereochemistry of acid-catalyzed cleavage of 3-chloro- and 3-bromonortricyclene in deuterated medium. Evidence for edge protonation of nortricyclenes

Die Synthese von 7‐anti‐substituierten 2‐exo‐ und 2‐endo‐Norbornanolen. Norbornanreibe. 13. Mitteilung

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