Eribulin Mesylate Intermediate Synthesis via Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing processes for preparing eribulin mesylate are sensitive to reaction conditions and have a long pathway, resulting in low yields of the key intermediate compound of formula (2).
Innovation Solution
A process involving specific steps such as Wittig reaction, selective deprotection, cyclization, hydrogenation, and reduction using intermediates like compound (3) with diol and silyl protecting groups, which includes Horner-Wadsworth-Emmons, Nozaki-Hiyama-Kishi reactions, and ester reduction to obtain compound (2) with improved yields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the prior processes are used for preparing compound (2), then the reaction pathway is established, but the yield of compound (2) is lowered due to sensitivity to reaction conditions and long pathway
Solution Approach 1:
The synthesis pathway is divided into multiple discrete steps with specific protecting group strategies. Compound (1) is converted to compound (2) through sequential transformations including Wittig reaction, selective deprotection, cyclization, hydrogenation, and reduction steps. Each step is optimized independently to maximize overall yield while managing complexity through systematic segmentation of the synthetic route.
Solution Approach 2:
Protecting groups are strategically installed before key transformations to prevent unwanted side reactions. The diol protecting group is introduced early in the sequence and maintained through subsequent steps, allowing reactions to proceed under conditions that would otherwise be incompatible with free diol functionality. This preliminary protection enables higher yields in sensitive transformation steps.
2Productivity
If the prior processes are used for preparing compound (2), then the synthesis pathway is established, but the process efficiency is reduced due to long reaction pathway
Solution Approach 1:
Multiple transformations are combined into unified reaction sequences where possible. For example, the cyclization step simultaneously forms the cyclic ether structure and establishes key stereochemistry, eliminating the need for separate steps. The protecting group strategy is designed to require minimal intervention steps, merging protection and deprotection operations into efficient sequences that reduce overall pathway length.
Solution Approach 2:
Reaction conditions are optimized for each transformation step to maximize rate and yield. Temperature, solvent, catalyst, and reagent stoichiometry are carefully controlled to accelerate reactions without compromising selectivity. These parameter optimizations reduce reaction times and minimize the number of isolation/purification cycles needed, thereby improving overall process efficiency despite the multi-step nature of the synthesis.
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
The process achieves high yields of the key intermediate compound (2) for eribulin mesylate production, enhancing the efficiency and effectiveness of the synthesis.
Implementation Method 1
subjecting a compound of the following formula (4) to Wittig reaction to obtain a compound of the following formula (5)
Implementation Method 2
which includes Horner-Wadsworth-Emmons
Implementation Method 3
which includes Nozaki-Hiyama-Kishi reactions
Implementation Method 4
subjecting the compound of the following formula (7) to hydrogenation to obtain a compound of the following formula (8)
Implementation Method 5
reducing an ester group of the compound of the following formula (8)
Data Source
AI summary
The present invention relates to a process for preparing an intermediate for the preparation of eribulin mesylate with high yields, and an intermediate therefor.