Caronic anhydride, systematic name 6,6-Dimethyl-3-oxabicyclo[3.1.0]hexane-2,4-dione, CAS 67911-21-1, is a rigid bicyclic cyclic anhydride with fused cyclopropane and anhydride ring structure. Its unique compact double-ring skeleton cannot be replaced by ordinary linear anhydrides, which makes it an irreplaceable structural building block for small-molecule bioactive compound synthesis.

The product is refined through multi-stage recrystallization process, with strict control over residual solvent, single impurity and water content. It maintains stable molecular configuration during low-temperature storage and organic synthesis reactions, widely adopted in pilot amplification, laboratory chiral synthesis and fine chemical customization research.

The fused cyclopropane ring owns strong structural rigidity, no ring-opening fracture under heating below 120 ℃, keeps fixed three-dimensional conformation in amidation and esterification reactions, effectively improving target product yield and chiral purity.

Anhydride functional group easily reacts with water vapor to generate caronic acid dicarboxylate, which loses synthetic activity. Strict airtight and nitrogen-filled packaging is required for whole transportation and storage cycle to prevent hydrolysis failure.

Soluble in common polar organic solvents; insoluble in water and saturated alkane solvents, matching the solvent system of fine chemical synthetic lines.

Long-term heating below 120 ℃ keeps complete molecular structure; continuous heating above 200 ℃ will trigger irreversible ring-opening degradation, so high-temperature distillation and heating are forbidden during processing.

Dual carbonyl anhydride structure supports high-efficiency amidation, esterification and ring-opening coupling reactions, rapidly constructing cyclopropane chiral fragments of bioactive molecules with mild reaction conditions and few by-products.

Residual solvent, heavy metal, single unknown impurity and moisture are all controlled within industry inspection limits, fully meeting raw material standards for pilot and commercial mass production.

Uniform white fine crystal form without agglomeration, consistent particle size across batches, uniform dissolution rate in reaction solvents and highly repeatable experimental data for synthetic routes.

When stored at 2–8 ℃ filled with nitrogen, the effective component decline rate is extremely low, long-term storage can maintain stable chemical activity without extra purification before use.

1. Core synthetic fragment for cyclopropane-containing bioactive molecular construction.
2. Essential precursor for heterocyclic skeleton synthesis of bioactive small-molecule materials.
3. General chiral building block for laboratory asymmetric catalytic experiments.
4. Raw material for fine chemical industry, applied to prepare special curing agents and liquid crystal material intermediates.
5. Organic ligand for rare earth metal complex synthesis, widely used in coordination chemistry laboratory research.

1. Storage condition: Seal in airtight containers filled with nitrogen, store at constant temperature 2–8 ℃, keep away from sunlight and heat sources.
2. Isolation requirement: Separate from water, humid air, strong alkali and strong oxidants to avoid hydrolysis and side reactions.
3. Operation specification: Operate inside ventilated fume hood, wear dust-proof mask, chemical-resistant gloves and goggles, prevent skin, eye and respiratory irritation caused by crystal dust.
4. Packaging reminder: Reduce frequent opening of packaging barrel/bottle, complete feeding operation quickly to minimize contact with air moisture.