Macrocyclic Ketone Synthesis via N2O Oxidation and Hydrogenation
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Solution Overview
Problem
Current methods for synthesizing saturated macrocyclic ketones like muscone are inefficient due to the limited cleavage of C=C double bonds during oxidation with N2O, resulting in low yields and complex processes.
Innovation Solution
A process involving the partial conversion of cyclic olefins with dinitrogen monoxide to form ketones, followed by selective hydrogenation to achieve saturated ketones, with controlled reaction conditions such as temperature, pressure, and catalyst usage to optimize yield and product purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If oxidation with N2O is used to convert cyclic olefins to ketones, then the reaction conditions are mild and selective, but the C=C double bond cleavage does not occur or occurs to only a minor extent
Solution Approach 1:
The process is divided into two distinct stages: first, selective oxidation of the cyclic olefin to form an unsaturated ketone with preserved C=C bond; second, separate hydrogenation of the C=C bond to form the saturated ketone. This segmentation allows each step to be optimized independently, achieving both high selectivity in oxidation and high yield in the final saturated product.
Solution Approach 2:
The oxidation step is performed first to convert the cyclic olefin to an unsaturated ketone before the hydrogenation step. This preliminary action creates an intermediate compound that can then be selectively hydrogenated in a subsequent step, ensuring that the oxidation conditions do not need to force C=C cleavage while still achieving the desired transformation.
2Productivity
If traditional oxidation methods are used to cleave C=C double bonds, then the yield of saturated ketone improves, but the process becomes more complex and requires additional reagents
Solution Approach 1:
The complex traditional one-step oxidation process is segmented into two simpler steps: selective oxidation followed by hydrogenation. Each step uses straightforward, well-established chemistry rather than complex reagents or conditions, reducing overall process complexity while maintaining or improving yield.
Solution Approach 2:
The unsaturated ketone is used as an intermediary compound that bridges the starting cyclic olefin and the final saturated ketone. This intermediary allows the transformation to proceed through two simple, high-yielding steps rather than one complex step, simplifying the overall process.
3Manufacturing precision
If multiple steps are used to convert cyclic olefins to saturated ketones, then the selectivity of each step improves, but the overall process time increases
Solution Approach 1:
The oxidation and hydrogenation steps are designed to be continuous or easily sequential operations, with the unsaturated ketone intermediate being directly carried from the first step to the second. This continuity minimizes idle time and allows for efficient process integration, reducing the overall time penalty of using multiple 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 allows for the efficient production of saturated ketones like muscone with improved yields and simplified processes by controlling the reaction conditions, ensuring high selectivity and minimal side reactions.
Implementation Method 1
a cyclic olefin of the formula I is reacted with dinitrogen monoxide (N2O) to give the ketone of the formula II
Implementation Method 2
the ketone of the formula II is hydrogenated to the saturated ketone of the formula III
Data Source
AI summary
Ketones of the formula IIwhere A is optionally alkyl-substituted C2-C12-alkanediyl, R1 and R2 are each, independently of one another, C1-C6-alkyl, or R1 and R2 together form optionally alkyl-substituted C3-C10-alkanediyl, and R3 is hydrogen or C1-C6-alkyl, are prepared by reacting a cyclic olefin of the formula Iwith dinitrogen monoxide to form the ketone of the formula II. The ketone of the formula II can be further hydrogenated to form the saturated ketone of the formula III.Macrocyclic ketones of the formula III, e.g. muscone, are sought after as fragrances.