56345-01-8Relevant academic research and scientific papers
Preparation method of E-2-cyclopentadecenone
-
Paragraph 0018; 0026-0038, (2017/08/31)
The invention provides a novel method for synthesizing E-2-cyclopentadecenone by utilizing 2-hydroxy-cyclopentadecanone. The 2-hydroxycyclopentadecanone, metal oxide, concentrated sulfuric acid or concentrated phosphoric acid are added into a non-polar organic solvent and are subjected to elimination reaction to obtain the E-2-cyclopentadecenone. In the reaction, a catalytic amount of the metal oxide is added so that a condition that the elimination reaction cannot be realized through the concentrated sulfuric acid before becomes possible; the raw materials in the novel method are relatively cheap; reaction conditions are moderate, the operation is simple and the production cost is reduced so that the novel method is very suitable for industrialized production.
A novel, short and repeatable two-carbon ring expansion reaction by thermo-isomerization: Easy synthesis of macrocyclic ketones
Nagel, Matthias,Hansen, Hans-Ju?rgen,Fra?ter, Georg
, p. 275 - 279 (2007/10/03)
A novel two-carbon ring enlargement procedure, in which medium- and large-ring 1-vinylcycloalkanols are thermoisomerized in a flow reactor system at temperatures of 600°C to about 650°C, produces the isomeric ring-expanded cycloalkanones directly and efficiently. This two-step ring expansion protocol can easily be applied several times successively. For e.g., the musk odorant cyclopentadecanone (Exaltone?) is prepared from cycloundecanone in two repetitive cycles. Thermo-isomerization of the corresponding ethynylic cycloalkanols gives in moderate yields the bishomologous α,β-unsaturated macrocyclic (E)-2-cycloalkenones. A reaction mechanism via alkyl hydroxyallyl biradical intermediates is proposed.
