Boerma, Jan Albertus

English

The research described in this thesis can be divided into two parts: reactions of derivatives of 3, 3,6,6-tetramethylthiepane (Chapter II) and efforts to synthesize tetra-t-butylethylene (Chapters III, IV and V). Chapter I deals with some literature concerning strain in organic compounds, especially in ethylenes. The reactions of some derivatives of 3,3,6,6-tetramethylthiepane (8) are described in Chapter II. ... Zie: Summary

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   University of GroningenDe synthese van sterisch gehinderde alkenen reacties aan 3,3,6,6-tetramethylthiepaanBoerma, Jan AlbertusIMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:1972Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Boerma, J. A. (1972). De synthese van sterisch gehinderde alkenen reacties aan 3,3,6,6-tetramethylthiepaan. s.n.CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 04-06-2022SummaryThe research descr ibed in th is thesis can be div ided in-to  two par ts :  reac t ions  o f  der " iva t ives  o f  3 ,  3 ,6 ,6 - te t rame-thyl th iepane (Chapter I I )  and ef for ts to synthesize tetra- / -buty lethylene (Chapters I I I ,  IV and V),Chapter I  deals wi th some l i terature concerning strainin organic compounds, especial ly in ethylenes.T h e  r e a c t i o n s  o f  s o m e  d e r i v a t i v e s  o f  3 , 3 , 6 , 6 - t e t r a m e -thyl th iepane (B) are descr ibed in Chapter I I .  These reac-t ions are compared with the react ions of  comparable der i -va tes  o f  2 ,2 ,  5 ,  5 - te t ramethy lhexane (9 ) .  In f luences  ar is ingfrom the cycl ic nature of  B were invoked to explain di f fer-ences relat ive to noncycl ic'*t7+compounds  f o r  t he  benz i l i c  ac id  rea r rangemen t  o f  B  (X=Y=O)and  fo r  t he  Wo l f f  r ea r rangemen t  (X=O,  Y=Nz) .  The  ch lo ro -ketone of  type B d id  not  g ive a  normai  Favorsk i i  react ionwi th  base.  The hydroxyketone of  type B was found to  g iveannela t ion react ions wi th  phosgene and th iony lch lor ide.  Inthe  reac t i on  o f  B  (X=Y=OH)  w i t h  su l f u r i c  ac id  t he  su l f u ra tom par t ic ipated t ransannular ly ,  as  \Mas found in  the re-act ion o f  the hydroxyketone of  type B wi th  d ibromotr iphe-ny lphosphine.  Some ins ight  in to  the conformat ion of  thecompounds t4  is  for thcoming f rom the observat ion o f  t rans-annular  hydrogen br idg ing .Chap te rs  I i I  and  IV  dea l  w i t h  e f f o r t s  t o  syn thes i ze  t e t ra -Í - bu t y te thy lene  (7 ) .  The  s ta r t i ng  compounds  f o r  t hese  syn -theses  we re  de r i va t i ves  o f  3 ,  3 ,  5 ,  5 - t e t rame thy l t e t rahyd ro -th i apy ran -  4 -  one  (10 )  (Chap te r  I I I ) ,  3 ,  5 - t e t rame thy l t h i apy -r a n - 4 - o n e  ( 1 1 )  ( C h a p t e r  I V )  a n d  2 , 2 ,  4 ,  4 - t e t r a m e t h y l c y c L o -bu taned ione  (12 )  (Chap te r  IV ) .  I t  was  hoped  tha t  t he  s ta r t -i n g  c o m p o u n d s  ( 1 0 ,  1 1  a n d  1 2 )  c o u l d  b e  " d i m e r i z e d "  a t  t h eca rbony l f unc t i ons .  The  s te r i c  h i nd rance  i n  t he  d imer i zedp roduc t s  cou ld  t hen  be  en la rged  by  d i f f e ren t  sequences  o freac t i ons .  The  h igh l y  s t r a i ned  compound  7  cou ld  no t  bes y n t h e s i z e d  b y  u s .l t ,8B 3-T\ /XXt - ^9 - UXX7-V/ \ -S. -.Rsx ) (\  /  t ^ , -^ í  \R '7 \ ' r - r r{^ 4"':ra' -<,l 0  l 1ofo1 2The  sub jec t  o f  r esea rch  desc r i bed  i n  Chap te r  V  i s  t hesynthes is  and some phys ica l  and chemica l  proper t ies  o fsome  1 ,  1 -  dL - t - bu t y l e thy lenes  (13 ) .  These  compounds  \ / e resynthes ized by the promis ing sequence beginn i .ng f rom th ia-X,:,,-X\R1392diazo l ines (92) .  Th is  method was shown to  have i ts  l imi -ta t ions in  the synthes is  o f  a lkenes wi i t r  bu lky  subst i tuents .The  UV  spec t ra  o f  13  (R=Rr=a ry l )  do  no t  d i f f e r  s i gn i f i -cant ly  f rom the UV spect ra  o f  o ther  1 ,  1-d iary le thy lenes.The ethy len ic  double  bond in  13 proved to  be very  unre-act ive in  o le f in ic  addi t ion react ions.  I t  was shown that  thepheny l r i ngs  i n  13  (R=Rr=pheny l )  do  no t  g i ve  e lec t roph i l i csubst i tu t ions under  normal  condi t ions.  Th is  lack o f  reac-t iv i ty  was exp la ined by assuming a perpendicu lar  pos i t ionof  the pheny l  r ings and the double  bond in  13,  by whichthe ethy len ic  double  bond destab i l izes the Wheland in ter -mediate  in  e lect rophi l ic  aromat ic  subst i tu t ion react ions.

De synthese van sterisch gehinderde alkenen reacties aan 3,3,6,6-tetramethylthiepaan

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De synthese van sterisch gehinderde alkenen reacties aan 3,3,6,6-tetramethylthiepaan

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