A Study on Camphor Derivatives and Its Applications: A Mini-Review

: Natural compounds are the prominent sources for the synthesis of abundant biologically active substances in medicinal chemistry. Camphor exists in two enantiomeric forms i.e., R and S, or both, which are readily obtainable. Camphor is a small molecule with chirality property that binds to some active site, together with its low cost and convenience to transform into synthetically useful derivatives and one of the most important monoterpenoids widely spread in plants and has been used as starting material for the various camphor based derivatives which exhibit several biological activities include antimicrobial, antiviral, antioxidant, analgesic and anti-cancer. Many of those simple derivatives are commercially available in the form of camphor sulfonic acid or ketopinic acid that can be easily be produced from camphor. This compound is primarily used as a chiral starting material in the enantiospecific synthesis of natural products is because of its available methods for the direct or indirect introduction of functionality at C-3, C-5, C-8, C-9, and C-10 carbon atoms. In this study, heterocyclic compounds derived from camphor are arranged in different groups as Camphor-Derived Simple Heterocycles, Fused Camphor-Derived Heterocycles, Spiro Camphor-Derived Heterocycles, Ring Expanded Camphor-Derived Heterocycles and Camphor derived metal complexes. This study summarizes the transformations of camphor and its derivatives along with their biological activities.

5-Nitro-N 2,N 3-bis[(1R,2R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl]isophthalamide dichloromethane hemisolvate

The asymmetric unit of the title hemisolvate, C28H39N3O4·0.5CH2Cl2 contains two isophthalamide camphor derivatives and one dichloromethane solvent molecule. In the crystal, the chiral molecules are connected into [100] stacks by N—H...O and C—H...O hydrogen bonds. The stacks are consolidated by C—H...N and C—H...Cl as well as further C—H...O interactions.

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

Compounds containing two alkyne groups in close vicinity at the rigid skeleton of camphorsulfonamide show unique reactivities when treated with electrophiles or catalytic amounts of platinum(II). The formed product structures depend not only on the reagents used but also on the substituents attached to the triple bonds. Cycloisomerisations with perfect atom economy lead to polycyclic heterocycles that resemble to some extent the AB ring system of paclitaxel. Herein, we present practical synthetic methods for the selective synthesis of precursor dialkynes bearing different substituents (alkyl, aryl) at the triple bonds, based on ketals or an imine as protecting groups. We show for isomeric dialkynes that the reaction cascade induced by Pt(II) includes ring annulation, sulphur reduction, and ring enlargement. One isomeric dialkyne additionally allows for the isolation of a pentacyclic compound lacking the ring enlargement step, which we have proposed as a potential intermediate in the catalytic cycle.

Identification of camphor derivatives as novel M2 ion channel inhibitors of influenza A virus

Amantadine derivatives have been the only drugs marketed as M2 inhibitors of influenza A for decades.