Acetic Acid → 2-Ethylidene-17beta-methoxy-5alpha-androstan-3-one

HRID 848772Notes

Reaction equation

HRID 848772 reaction equation
[CH3:1][O:2][C@H:3]1[CH2:8][CH2:7][C@H:6]2[C@H:9]3[C@H:19]([CH2:20][CH2:21][C@:4]12[CH3:5])[C@:17]1([CH3:18])[C@H:12]([CH2:13][C:14](=[O:22])[CH2:15][CH2:16]1)[CH2:11][CH2:10]3.[OH-].[K+].[CH:25](=O)[CH3:26].C(O)(=O)C>C(O)C>[CH:25](=[C:15]1[CH2:16][C@@:17]2([CH3:18])[C@@H:12]([CH2:11][CH2:10][C@@H:9]3[C@@H:19]2[CH2:20][CH2:21][C@@:4]2([CH3:5])[C@H:6]3[CH2:7][CH2:8][C@@H:3]2[O:2][CH3:1])[CH2:13][C:14]1=[O:22])[CH3:26]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 177AcetaldehydeHCID 14797Potassium Hydroxide2×HCID 1104493517beta-Methoxy-5alpha-androstan-3-one

Product 1

HCID 705636042-Ethylidene-17beta-methoxy-5alpha-androstan-3-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A mixture of 17β-methoxy-5α-androstan-3-one (U.S. Pat. No. 3,301,850, Example 14, 8 g.), potassium hydroxide (2.1 g.) and acetaldehyde (5 ml.) in absolute ethanol (500 ml.) is stirred for 16 hours under nitrogen. The potassium hydroxide is then neutralized with acetic acid and the mixture concentrated to about 100 ml. Water is added and the product is extracted with diethyl ether. After the diethyl ether is removed the steroid is chromatographed over silica gel and then alumina. The appropriate fractions are pooled and concentrated to give both isomers of the product, IR (neat) 1720 and 1690 cm-1 ; MS (m/e) 330; NMR (CDCl3) 0.79, 0.78, 0.83, 1.72, 3.22, 3.35 and 6.75 δ; and UV (ethanol) λ=246 nm (ε=4,300).

Workup

  1. concentrationthe mixture concentrated to about 100 ml
  2. additionWater is added
  3. extractionthe product is extracted with diethyl ether
  4. customAfter the diethyl ether is removed the steroid
  5. customis chromatographed over silica gel
  6. concentrationconcentrated
  7. customto give both isomers of the product, IR (neat) 1720 and 1690 cm-1

Sources & evidence

ORD record
ord-1bff365f62804e8d98762cd611174b66
Source dataset
uspto-grants-1981_10
Patent number
US04297350

Reaction notes

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