An anionic 8π electrocyclic reaction of 4-(diethoxyphosphoryl)-1,3,6-heptatriene derivatives was developed. Under the influence of a base, the substrate underwent deprotonation at the C5 position followed by the 8π electrocyclization of the resulting heptatrienyl anion. The subsequent Horner–Wadsworth–Emmons reaction in one pot, following the addition of an aldehyde, resulted in the production of the
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.