N-((1R,3R,6S)-7-oxabicyclo[4.1.0]heptan-3-yl)-2,2,2-trifluoroacetamide

This intermediate takes rigid 7-oxabicyclo[4.1.0]heptane as the core parent nucleus, with three chiral centers at positions 1, 3 and 6 with unique configuration. The amino group at position 3 is protected by trifluoroacetyl group (TFA); the TFA protecting group has excellent stability, which can effectively avoid side reactions such as oxidation and condensation of amino group in subsequent reactions. It can be selectively removed under mild alkaline conditions (e.g., methanol/ammonia solution system) without destroying the chiral configuration of the parent nucleus, meeting the requirements of downstream precise synthesis. The bicyclic rigid structure can also provide a specific spatial conformation for target products and improve the binding efficiency of drug targets.

In terms of physicochemical properties, it appears as white to off-white crystalline powder, easily soluble in common organic solvents such as dichloromethane, tetrahydrofuran, ethyl acetate and acetonitrile, slightly soluble in water and poorly soluble in n-hexane and petroleum ether. It has good stability under room temperature and dry conditions, with trifluoroacetyl group not easy to fall off. High temperature (> 90℃), strong acid, strong base, direct strong light and long-term exposure to humid air should be avoided.

For applications, it is mainly used in the synthesis route of Lefamulin Acetate (a novel pleuromutilin antibiotic for the treatment of community-acquired bacterial pneumonia), and its chiral configuration directly determines the efficacy and selectivity of downstream APIs. Meanwhile, it can be used as a chiral intermediate in the R&D of other anti-infective and central nervous system drugs, and also as a precursor to prepare chiral ligands, facilitating transition metal-catalyzed asymmetric hydrogenation and addition reactions to improve the chiral purity of products.

For industrial application, strict purity requirements are needed, with chiral purity (ee value) ≥ 99% and chemical purity ≥ 98.5%. It should be sealed and stored in a dry, cool and well-ventilated place, separated from oxidants, acids, bases and hygroscopic agents to prevent moisture absorption, caking and deterioration, ensuring the stability and conversion rate of subsequent synthesis reactions.