Chiral blocks for the synthesis of cyclopentanoids from [2 + 2]-cycloadduct of dichloroketene and dimethylfulvene
作者:N. A. Ivanova、N. P. Akhmetdinova、Z. R. Valiullina、V. A. Akhmet’yanova、O. V. Shitikova、A. N. Lobov、K. Yu. Suponitskii、L. V. Spirikhin、M. S. Miftakhov
DOI:10.1134/s1070428012030190
日期:2012.3
Opening of the alpha,alpha-dichlorocyclobutanone ring in the [2+2]-cycloadduct of dichloroketene and dimethylfulvene with (+)-alpha-methylbenzylamine gave diastereoisomeric 2-dichloromethyl-5-isopropylidene-N-(alpha-methylbenzyl)cyclopent-3-ene-1-carboxamides, and hydrolysis of the latter at the dichloromethyl group afforded the corresponding bicyclic aminals which can be readily separated by chromatography on silica gel. The subsequent removal of the alpha-methylbenzylamine fragment via reduction and hydrolysis resulted in the formation of enantiomerically pure (-)- and (+)-6-(1-methylethylidene)-3,3a,6,6a-tetrahydro-1H-cyclopenta[c]-furan-1-ones.