Etonogestrel Synthesis via Selective 11-Ketone Oxidation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current synthesis routes for etonogestrel and desogestrel in hormonal contraceptives are labor-intensive and costly, lacking efficient and cost-effective alternatives.
Innovation Solution
A process involving the synthesis of 20-yn-11-methylene-3-dithioacetal steroid derivatives using deprotection with periodic acid, thallium nitrate, or stabilized 2-iodoxybenzoic acid and β-cyclodextrin, reducing the complexity and cost of producing etonogestrel and desogestrel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional synthesis routes are used for etonogestrel and desogestrel, then the products can be manufactured, but the process is labor-intensive and costly
Solution Approach 1:
The synthesis route is divided into distinct modular stages: oxidation of 11β-hydroxy-18-methylnordione to the triketone, selective protection of carbonyl groups as ethylene acetals, deprotection to yield the 11-keto derivative, and final conversion to etonogestrel or desogestrel. Each stage is optimized independently, improving overall manufacturing efficiency while controlling costs through targeted intermediate isolation and reuse of reagents.
2Manufacturing precision
If selective protection of carbonyl groups is performed, then the 11-ketone can be obtained, but the process requires multiple protection and deprotection steps
Solution Approach 1:
Ethylene glycol is used as a protecting group intermediary to selectively mask the 3-keto and 17-keto carbonyl groups as ethylene acetal derivatives during the oxidation step. This allows selective formation of the 11-ketone functionality. The protecting group is then cleanly removed under acidic conditions to yield the desired 11-keto-3,17-diol intermediate, demonstrating high selectivity despite the multi-step nature of the process.
Solution Approach 2:
The oxidation conditions are carefully controlled by adjusting parameters such as the oxidant type (sodium periodate, TEMPO), solvent composition (acetonitrile/water mixtures), temperature, and pH. These parameter optimizations enable selective oxidation at the C-11 position while minimizing side reactions, achieving high manufacturing precision even through multiple steps.
3Manufacturing precision
If multiple synthesis steps are used for introducing 11-functionality, then the desired steroid derivative can be obtained, but five steps are required
Solution Approach 1:
The 3-keto and 17-keto groups are pre-protected as ethylene acetals before the oxidation step. This preliminary protection prevents unwanted oxidation at these positions and directs the oxidant specifically to the C-11 hydroxyl group. By preparing the molecule in advance with appropriate protecting groups, the subsequent oxidation proceeds in high yield and selectivity, reducing the need for additional purification and correction steps.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method provides a more efficient and cost-effective route for synthesizing etonogestrel and desogestrel, potentially improving the manufacturing process for hormonal contraceptives by simplifying the synthesis steps and reducing production costs.
Implementation Method 1
wherein etonogestrel is obtained by deprotection of the 3-dithioacetal using periodic acid, thallium nitrate or stabilized 2-iodoxybenzoic acid (SIBX)
Implementation Method 2
stabilized 2-iodoxybenzoic acid (SIBX) and β-cyclodextrin (β-CD)
Data Source
AI summary
The present invention relates to a synthesis route and to steroid derivatives of general formula VI and VII useful in the synthesis of desogestrel and etonogestrel.