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Carbonylierende Ringerweiterung, 4. Diastereoselektive Synthesen von Bicyclo[3.2.1]oct‐3‐en‐2,8‐dionen durch doppelte Carbonylierung von ( R )‐(‐)‐α‐Phellandren
Author(s) -
Eilbracht Peter,
Hittinger Christel,
Kufferath Klaus,
Henkel Gerald
Publication year - 1990
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19901230522
Subject(s) - bicyclic molecule , chemistry , stereospecificity , ring (chemistry) , stereochemistry , ene reaction , carbonylation , organic chemistry , catalysis , carbon monoxide
Carbonylating Ring Enlargement, 4 1) . – Diastereoselective Syntheses of Bicyclo[3.2.l]oct‐3‐ene‐2,8‐diones by Double Carbonylation of (It)‐(‐)‐α‐Phellandrene In order to clarify the stereochemistry of the carbonylating ring enlargement of cyclohexadiene complexes 1 to complexed seven‐membered ring ketones 2 and the further carbonylation to bicyclo[3.2.1]oct‐3‐ene‐2,8‐diones 3 the exo and endo isomers of ( R )‐(‐)‐α‐phellandrene complex 7 were synthesized in pure form and in various isomeric ratios and converted. The optically active ring‐enlargement products 11 and 12 obtained therefrom, as well as the enantiomerically pure bicyclooctenes 20–22 , implicate a stereospecific reaction course under retention of the configuration predetermined by the starting material 6 and its complexes 7 . This was confirmed by an X‐ray determination of the absolute configuration of exo ‐ 12 . Thus, the method is suitable for the diastereoselective synthesis of bicyclo[3.2.1]oct‐3‐ene‐2,8‐diones 3 from 1,3‐cyclohexadiene complexes 1 .