ChemicalBook CAS DataBase List Teprenone Impurity 20

Teprenone Impurity 20 synthesis

6synthesis methods

Product Name:Teprenone Impurity 20
CAS Number:1117-51-7
Molecular formula:C18H30O
Molecular Weight:262.43

40716-66-3 Synthesis

40716-66-3
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$6.00/5g

116-11-0 Synthesis

116-11-0
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$10.00/5g

1117-51-7
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1117-52-8 Synthesis

(5E,9E)-6,10,14-Trimethylpentadeca-5,9,13-trien-2-one

1117-52-8
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Yield:-

Reaction Conditions:

Stage #1: (E)-3,7,11-trimethyl-1,6,10-dodecatrien-3-ol;2-Methoxypropene;phosphoric acid in acetone at 160; for 16 h;
Stage #2: with sodium acetate in acetone at 25; for 0.5 h;Product distribution / selectivity;

Steps:

1; 2; 3

A 1.0 liter stainless steel batch reactor (Medimex - High Pressure) with electrical heating and water cooling system in the jacket, a pressure sensor and stainless steel propeller was loaded with a mixture of 1.2885g of a solution of 18w% H₃PO₄ in acetone (2.37 mMol, 0.3 Mol%) and 179.5g of E-nerolidol (0.790 MoI). 225g of isopropenylmethyl ether (IPM, 3.01 MoI, 3.81 equivalent) were added. Under stirring (500 rpm) the mixture was heated to 160⁰C within two hours. After 16 hours total reaction time the reaction mixture was cooled to 25°C, drawn from the reactor under reduced pressure and stirred with 2g of sodium acetate for 30 minutes. After filtration over a 5μm Teflon membrane the low- boilers were removed in two steps (at lOmbar and 0.05mbar on pump) in a Rota vapor at 40⁰C. The crude product (yield 93.1%, selectivity 0.94) was distilled in a 500ml two- necked round-bottomed flask with PT 100, magnetic stirrer, Liebig condenser, Anschtz Thiele separator, cold trap and high- vacuum pump in an oil bath. At a bath temperature of 140⁰C, an inner temperature of 125 - 127°C, a head temperature of 118 - 122°C and an absolute pressure of 0.03 - 0.02 mbar (on the pump) a mixture OEIE- and (5Z,9E)- farnesyl acetone was obtained in a yield of 86%. A pre-fraction with a mixture of EIE- and (5Z,9￡)-farnesyl acetone was obtained in a yield of 3.7% at 67 - 140⁰C, 44.5 - 123°C, 27.3 - 111°C, respectively, and 0.03mbar (on pump). Total yield of the main- and pre- fraction 89.7%, selectivity 0.9). The .E/.E-farnesyl acetone was separated from the (5Z/9E)- farnesyl acetone by distillation. The product was characterized by ¹H and ¹³C-NMR spectroscopy. The purity was determined by gas chromatography.E/E-FA 300 MHz ¹³C-NMR (CDCl₃): δ (ppm, TMS) = 208.8, 136.4, 135.0, 131.3, 124.4, 124.0, 122.5, 43.8, 39.7, 39.6, 29.9, 26.8, 26.5, 25.5, 22.5, 17.7, 16.0 (2C).; Example 2In the same manner as described in Example 1 starting from 199g .E-nerolidol, 1.38g catalyst solution and 3.15 equivalents of IPM there was obtained a mixture of E/ E- and (5Z,9￡)-farnesyl acetone in a yield of 89.8%, selectivity 0.90 (crude) and of 87.4% (Total of main- and pre-fraction, after separation of the low- and high-boilers) with a selectivity of θ.87.; Example 3In the same manner as described in Example 1 staring from 224.4g .E-nerolidol, 1.56g of catalyst solution and 2.5 equivalents of IPM there was obtained a mixture OEIE- and (5Z,9￡)-farnesyl acetone in a yield of 88.2%, selectivity 0.88 (crude) and of 86.1% (Total of main- and pre-fraction, after separation of the low- and high-boilers) with a selectivity of θ.86.