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Synthesis of Enantiomerically Pure trans ‐1,2‐Disubstituted Cyclopentanes and Cyclohexanes by Intramolecular Allylsilane Addition to Chiral Alkylidene‐1,3‐dicarbonyl Compounds
Author(s) -
Tietze Lutz F.,
Schünke Christian
Publication year - 1998
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(199810)1998:10<2089::aid-ejoc2089>3.0.co;2-c
Subject(s) - cyclopentanes , cyclohexanes , chemistry , knoevenagel condensation , intramolecular force , stereocenter , malonic acid , moiety , stereochemistry , medicinal chemistry , organic chemistry , enantioselective synthesis , catalysis
Enantiomerically pure trans ‐1,2‐disubstituted cyclopentanes 14 and cyclohexanes 15 bearing three stereogenic centers can be synthesized highly selectively by Lewis acid induced intramolecular cyclizations of chiral alkylidene‐1,3‐dicarbonyl compounds 8 and 9 . The best results were obtained using SnCl 4 and the substrates 8d and 9d , which contain an oxazolidinone moiety derived from ( S )‐phenylalanine. In these reactions, 10d was formed from 8d in a 98:1:1 ratio, while 11d was formed from 9d in a 99:1 ratio, both in 87 % yield. The configuration of the major products 10d and 11d was proven by X‐ray analysis. Reduction of 10d and 11d with LiAlH 4 led to 14 and 15 , respectively, or to the diols 16 and 17 . The alkylidene‐1,3‐dicarbonyl compounds 8 and 9 were synthesized by Knoevenagel condensation of the respective allylsilane carbaldehydes 6 and 7 with the malonic acid derivatives 5a–d .