Synthesis of Methyl-substituted 1-Cyclopentene-1-carboxylates and Related Compounds
作者:Akira Takeda、K\={o}ichi Shinhama、Sadao Tsuboi
DOI:10.1246/bcsj.50.1831
日期:1977.7
The treatment of methyl-substituted 1-chloro-2-oxo-1-cyclohexanecarboxylic esters (7a–e) with anhydrous Na2CO3 in refluxing xylene gave the corresponding methyl-substituted 1-cyclopentene-1-carboxylic esters (1a–e). Several intermediates important in the synthesis of natural products, such as 4,4-dimethyl-1-cyclopentene-1-carbaldehyde (9), 5-methyl-1-cyclopentene-1-carbaldehyde (12), α-(3-methyl-1
Synthetic photochemistry. Elaboration of the tricyclo[6.3.0.0]-undecane (‘hirsutane’) carbon skeleton by intramolecular photocyclisations of dicyclopent-1-enylmethanes
作者:Joseph S. H. Kueh、Michael Mellor、Gerald Pattenden
DOI:10.1039/p19810001052
日期:——
addition of methanol to the presumed intermediate bicyclo[2.1.0]pentane (11), producing the cis,syn,cis-tricyclo[6.3.0.0]undecane (12) in >90% yield. The general method is applied in a synthesis of the hirsutane carbon skeleton [viz. (19)→(20)] found in hirsutic acid (7) and related natural sesquiterpenes.
internal cyc1opropanation of dienes 23 or cyc1opropanation of enone 25 followed by the thermolytic rearrangements of cyclopropanes 24, 39, 42, 45, and 48 to furnish triquinanes 26 and 40. An investigation of electronic effects affecting the diradical cleavage of viny1cyclopropanes was performed. The triquinanes 26 or 40 were transformed to the title compounds by reductive operations at C-9. The equilibration