3,20-Bis(ethylenedioxy)pregna-5,7-diene
[CAS# 19592-55-3]

Identification

• Classification: Natural product >> Steroidal compound
• Name: 3,20-Bis(ethylenedioxy)pregna-5,7-diene
• Synonyms: 10,13-dimethyl-17-(2-methyl-1,3-dioxolan-2-yl)spiro[1,2,4,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,2'-1,3-dioxolane]
• Molecular Formula: C₂₅H₃₆O₄
• Molecular Weight: 400.55
• CAS Registry Number: 19592-55-3
• EC Number: 243-175-0
• SMILES: C[C@]12CC[C@H]3C(=CC=C4CC5(CC[C@]34C)OCCO5)[C@@H]1CC[C@@H]2C6(C)OCCO6

Properties

• Density: 1.179±0.1 g/cm³, Calc.^*
• Melting point: 186.5-188.5 ºC
• Boiling point: 511.407±50.0 ºC (760 mmHg), Calc.^*
• Flash point: 124.204 ºC, Calc.^*
• Index of refraction: 1.572 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Hazard Statements: H302-H312-H315-H319-H332-H335-H410-H413
• Precautionary Statements: P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P317-P319-P321-P330-P332+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H312
Specific target organ toxicity - single exposure	STOT SE	3	H335
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315

Discovory and Applicatios

3,20-Bis(ethylenedioxy)pregna-5,7-diene is a synthetic steroidal compound derived from the structural backbone of pregnadiene, a class of steroidal molecules characterized by conjugated double bonds in the A and B rings of the steroid nucleus. The addition of ethylenedioxy groups at the 3 and 20 positions suggests a chemical modification that stabilizes or protects the corresponding ketone or hydroxyl functionalities, often serving as protecting groups during multistep syntheses or to alter pharmacokinetic properties such as metabolic resistance and bioavailability.

The discovery of such modified steroidal structures has roots in the mid-20th century, when significant efforts were undertaken to develop steroid-based drugs for hormonal regulation, anti-inflammatory effects, and treatment of cancers. The incorporation of dioxyalkyl groups into the steroid framework is a common approach to either block specific metabolic pathways or improve the selectivity of receptor binding. In particular, 3,20-Bis(ethylenedioxy) substitutions may be used to mask polar functional groups, improving lipophilicity and facilitating membrane permeability—an important factor in drug design.

This compound belongs to a broader class of modified steroids often used as intermediates in the synthesis of analogs with glucocorticoid, progestogenic, or anti-proliferative activities. Its structural similarity to natural steroids, combined with synthetic protection strategies, enables medicinal chemists to explore receptor-specific activity by modulating the spatial and electronic environment of key functional sites.

While specific therapeutic applications of 3,20-Bis(ethylenedioxy)pregna-5,7-diene remain limited in the literature, compounds with closely related structures have been investigated for their anti-inflammatory, anti-tumor, or antiviral properties. The 5,7-diene configuration in the steroid backbone is of particular interest because of its reactivity under ultraviolet irradiation, leading to potential photolytic transformation into active metabolites. In dermatological research, such 5,7-dienes are examined for their ability to form vitamin D analogs under UV exposure, although the presence of ethylenedioxy substitutions likely alters this behavior.

Synthetic routes to such compounds typically involve the use of protecting reagents like ethylene glycol in acidic conditions to form the acetal linkages at carbonyl positions, especially at the C3 and C20 positions. These positions are reactive centers in the steroid nucleus and are crucial for biological activity. Protecting these positions allows selective functionalization at other parts of the molecule and prevents unwanted side reactions in multistep synthetic pathways.

In structural studies, 3,20-Bis(ethylenedioxy)pregna-5,7-diene presents a rigid conformation typical of steroidal frameworks, with electron-rich dioxy groups influencing the molecular dipole and potential interactions with protein receptors. Computational modeling and crystallographic studies of similar molecules have shown that such modifications can either enhance or diminish receptor binding depending on the steric and electronic compatibility with active sites.

The compound may also serve as a useful probe in structure–activity relationship (SAR) studies within steroid-based drug development. By comparing biological responses of protected versus unprotected analogs, researchers can better understand the role of specific functionalities in bioactivity. Moreover, it can act as a precursor to deprotected or partially modified steroids through acid-catalyzed hydrolysis, allowing the stepwise study of functional contributions.

Though direct pharmacological data on 3,20-Bis(ethylenedioxy)pregna-5,7-diene are sparse, its chemical structure offers promise for exploration in hormone-related therapeutic areas or as a synthetic intermediate. The compound exemplifies the strategic use of protective group chemistry in steroid modification—a foundational technique in medicinal and synthetic organic chemistry.

References

2021. Berberine alters gut microbial function through modulation of bile acids. BMC Microbiology, 21(1).
DOI: 10.1186/s12866-020-02020-1

2021. Co-delivery of glial cell�derived neurotrophic factor (GDNF) and tauroursodeoxycholic acid (TUDCA) from PLGA microspheres: potential combination therapy for retinal diseases. Drug Delivery and Translational Research, 11(5).
DOI: 10.1007/s13346-021-00930-9

2018. Osteogenic Potential of Tauroursodeoxycholic Acid as an Alternative to rhBMP-2 in a Mouse Spinal Fusion Model. Tissue Engineering Part A, 24(5-6).
DOI: 10.1089/ten.tea.2016.0349