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Eine stereospezifische Synthese von syn ‐Bishomochinon über p ‐Benzochinon‐bis(äthylen)ketal
Author(s) -
Heller Jürg E.,
Dreiding André S.,
O'Connor B. R.,
Simmons H. E.,
Buchanan G. L.,
Raphael R. A.,
Taylor R.
Publication year - 1973
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19730560117
Subject(s) - chemistry , methylene , ethylene , hydrolysis , halogenation , medicinal chemistry , ether , stereospecificity , stereochemistry , organic chemistry , catalysis
The bis(ethylene)ketal of p ‐benzoquinone ( 6 ) has been prepared from the bis(ethylene)ketal of cyclohexane‐1,4‐dione ( 3 ) by bromination with bromine in ether followed by dehydrobromination with potassium t ‐butoxide. Two intermediate dibromides ( 4 and 5 ) were isolated and their constitutions as well as their configurations determined from spectroscopic properties. Partial hydrolysis of 6 furnished the mono(ethylene)ketal of p ‐benzoquinone ( 9 ), which was converted stereospecifically to syn ‐bishomoquinone ( 2 ) by the double addition of sodium dimethylsulfoxonium‐methylide. The intermediate mono(ethylene)ketals of syn ‐bishomoquinone ( 11 ) as well as of the mono(methylene) addition product ( 10 ) were also isolated.