tert-butyl ((1R,3R,4R)-3-hydroxy-4-mercaptocyclohexyl)carbamate

This intermediate takes chiral cyclohexane as the core skeleton, with three chiral centers at positions 1, 3 and 4 with unique configuration. The amino group at position 1 is protected by Boc group, and the hydroxyl group at position 3 and mercapto group at position 4 provide active sites for downstream reactions. The Boc protecting group has excellent stability, which can effectively avoid oxidation and condensation side reactions of amino group in subsequent reactions, and can be selectively removed under mild acidic conditions (e.g., TFA/dichloromethane system) without destroying the chiral configuration of cyclohexyl and the structure of dual functional groups, meeting the requirements of precise synthesis. The coexistence of hydroxyl and mercapto groups can participate in key reactions such as etherification and thioetherification, providing core support for the construction of Lefamulin Acetate parent nucleus structure.

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 methanol, slightly soluble in water and poorly soluble in n-hexane and petroleum ether. It has good stability under room temperature and dry conditions, but the mercapto group is prone to oxidation, so high temperature (> 80℃), strong oxidants, strong acids, strong bases, direct strong light and long-term exposure to humid air should be avoided to prevent oxidation deterioration of mercapto group and shedding of Boc group. It is recommended to store at 0-8 °C, isolated from air and light.

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 and dual functional group activity directly determine the efficacy and purity 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 and yield 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, stored separately (away from oxidants, halogens and hygroscopic agents), isolated from air and light to prevent deterioration and ensure the stability and selectivity of subsequent synthesis reactions.