Some work leading to syntheses of oestrone is presented. It was generally found necessary to protect the 1-carbonyl function in 5,6,7,7a-tetrahydro-8β-methylindane-1,5-dione before the introduction of alkyl groups at position 4. Alkylations of 2-methylcyclopentane-1,3-dione have been made and the results compared with similar studies on 2-methylcyclohexane-1,3-dione.
Some alkylations of 2-methylcyclopentane-1,3-dione
作者:David Rosenthal、Kenneth H. Davis
DOI:10.1039/j39660001973
日期:——
The alkylation of 2-methylcyclopentane-1,3-dione (A) with 2-(1-naphthyl)ethyl bromide gives only the O-alkylation product. Mixtures of C- and O-alkyl derivatives are obtained with (A) when phenacyl or 1-naphthacyl bromide is employed. The C- to O-alkyl ratio is lower with (A) than with the homologous diketone 2-methyl-cyclohexane-1,3-dione; a possible explanation for this difference is advanced.
allowing selective access to tertiary alkylated ketones and alkenes. The present approach features commercially available starting materials, broad substrate scope, general functional-group (including halogen, ester, nitrile, thioether) tolerance. Furthermore, we proposed plausible pathways to rationalize the divergent selectivity through preliminary mechanism study.