Condensation of ketones with dimethyl dimethylmaleate. A synthesis of calythrone
作者:M. Elliott、N. F. Janes、K. A. Jeffs
DOI:10.1039/j39690001845
日期:——
Condensation of 4-methylpentan-2-one with dimethyldimethylmaleate by use of sodium hydride gives calythrone (2-isovaleryl-4,5-dimethylcyclopentene-1,3-dione)(ca. 5%) but the main product is an ester, shown to be methyl 4-isovaleryl-2-methyl-3-oxocyclopentanecarboxylate and not as previously suggested. Reactions with acetone and acetophenone give only the corresponding cyclopentanone derivatives.
Elliot,M.; Jeffs,K.A., Proceedings of the Chemical Society, London, 1961, p. 374
作者:Elliot,M.、Jeffs,K.A.
DOI:——
日期:——
Synthesis of calythrone and related cyclopentene-1,3-diones via rearrangement of 4-ylidenebutenolides
作者:Nicholas G. Clemo、David R. Gedge、Gerald Pattenden
DOI:10.1039/p19810001448
日期:——
Treatment of 4-ylidenebutenolides with sodium methoxide in methanol results in rearrangement to the corresponding cyclopentene-1,3-diones in high yield. The general method is applied in a synthesis of calythrone [(1) from (18)] from Calythrix tetragona, and the relatedcyclopentene-1,3-diones [(15) from (14); (25) from (24); (27) from (26); (33) from (32); and (37) from (36)].