4-androstene-3,17-dione Synthesis

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4-androstene-3,17-dione Synthesis
Type	Semisynthesis
Chemical Name	4-androstene-3,17-dione
Systematic Name	androst-4-ene-3,17-dione
Reagents
Chemicals
Equipment
Reactions
Yield
Precautions
Primary Source	[1]

A 2-liter Erlenmeyer flasks with 500 ml of a sterile nutrient medium containing

1% of yeast extract

0.45% of disodium hydrogen phosphate

0.34% of potassium dihydrogen phosphate and

0.2% of "Tween" 80

adjusted to pH 6.7

is inoculated with a suspension of a dry culture of Mycobacterium spec. NRRL B-3805 and shaken at 30° C. at 190 rpm for 3 days.

Ten Erlenmeyer flasks (500 ml) with 100 ml of sterile nutrient medium each, containing

2.5% of corn steep liquor

0.3% of diammonium hydrogen phosphate

0.25% of soybean meal and

0.25% of "Tween" 80

adjusted to pH 7.0

are respectively inoculated with 5 ml of the Mycobacterium spec. germination culture and shaken at 30° C. at 220 rpm for 24 hours. Then, 100 mg of α-sitosterol, dissolved in 3.0 ml of dimethylformamide, is added to each culture, and fermentation is continued for another 96 hours at 30° C.

The combined cultures are extracted with ethylene chloride, the extract is concentrated under vacuum, and the residue is purified by chromatography over a silica gel column, thus obtaining, after recrystallization from diisopropyl ether, 160 mg of 4-androstene-3,17-dione.

In addition, 385 mg of unreacted α-sitosterol is recovered.

Alternative

As above, but using Mycobacterium spec. NRRL B-3683, 1,000 mg of α-sitosterol in total is reacted, worked up, and yields 140 mg of 1,4-androstadiene-3,17-dione besides 630 mg of unconverted α-sitosterol.