Dienedione


Dienedione, also known as estra-4,9-diene-3,17-dione, is a synthetic, orally active anabolic-androgenic steroid of the 19-nortestosterone group that was never introduced for medical use. It is thought to be a prohormone of dienolone. The drug became a controlled substance in the US on January 4, 2010, and is classified as a Schedule III anabolic steroid under the United States Controlled Substances Act. Previous to this, it was sold as a bodybuilding supplement within the United States, and often mistakenly marketed as a prohormone for trenbolone, a veterinary steroid. Prior to its scheduling, it was part of a number of supplements that were seized during FDA enforcement of Bodybuilding.com for selling unapproved new drugs. The actual active metabolite, dienolone, is almost identical to trenbolone structurally, but lacks the C11 double bond.
Dienedione use is also prohibited in horses. In addition, small amounts are endogenously produced in horses.

Applications

Dienedione finds use in the synthesis of more privileged steroids, e.g.:
  1. Trenbolone
  2. Mifepristone, Ulipristal, Asoprisnil, Onapristone, Org-34850 etc. Most of these agents are actually made from "ethylene deltenone" which is the ethyleneglycol cyclic ketal of dienedione, which is accompanied by reorganization of the diene regiochemistry. A methanol acetal protecting group is also very common.
  3. Dienogest One-pot method:
  4. Altrenogest The dimethyl acetal was used in this patent. Owing to the "chelate effect", cyclic ketals are more stubborn to remove than the dimethyl acetals, which means more forceful conditions that can lead to formation of impurities. Although, "ethylene deltenone" had been used in the prior state of the art.
  5. Trimegestone
  6. Estrogen

Chemistry

Synthesis

Dienedione was synthesized from dienolone in 90% yield.
The semi-synthetic chemical synthesis has been reported by Organon:
The starting material is called Sitolactone ; It is a commercially available product obtained by microbiological degradation of phytosterols which are waste products from the processing of soy. The first step consists of a Grignard reaction with 5-chloro 2-pentanone-neopentylacetal to give -5-hydroxy-7a-methyl-4-octahydro-1H-inden-1-one. Halogenation with chlorine gas in the presence of pyridine base gave -3,3--4,5-seco-estr-9-ene-5,17-dione . The hydrolysis of the ketal in weak acid led to -4,5-seco-estr-9-ene-3,5,17-trione . Lastly, an intramolecular aldol condensation in the presence of t-BuOK base completed the synthesis of dienedione.
Improvements to the general scheme have recently been reported in modern Chinese patents: