Synthesis of Enantiomerically Pure trans-1,2-Disubstituted Cyclopentanes and Cyclohexanes by Intramolecular Allylsilane Addition to Chiral Alkylidene-1,3-dicarbonyl Compounds

✍ Scribed by Lutz F. Tietze; Christian Schünke

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 277 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199810)1998:10<2089::aid-ejoc2089>3.0.co;2-c

✦ Synopsis

Enantiomerically pure trans-1,2-disubstituted cyclopentanes 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 14 and cyclohexanes 15 bearing three stereogenic centers can be synthesized highly selectively by Lewis acid induced 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 intramolecular cyclizations of chiral alkylidene-1,3dicarbonyl compounds 8 and 9. The best results were diols 16 and 17. The alkylidene-1,3-dicarbonyl compounds 8 and 9 were synthesized by Knoevenagel condensation of the obtained using SnCl 4 and the substrates 8d and 9d, which contain an oxazolidinone moiety derived from (S)-respective allylsilane carbaldehydes 6 and 7 with the malonic acid derivatives 5a-d. phenylalanine. In these reactions, 10d was formed from 8d