A Facile and Efficient Synthesis of (15R)-Latanoprost from Chiral Precursor Corey Lactone Diol

Organocatalyst-mediated, pot-economical total synthesis of latanoprost

The enantioselective total synthesis of latanoprost, an antiglaucoma agent, has been accomplished with excellent diastereo- and enantioselectivities in a pot-economical manner using six reaction vessels. An enantioselective Krische allylation was conducted in the first pot. In the second pot, olefin metathesis, silyl protection, and hydrogenolysis proceeded efficiently. In the third pot, an organocatalyst-mediated Michael reaction proceeded with excellent diastereoselectivity. The fourth pot involved a substrate-controlled Mukaiyama intramolecular aldol reaction and elimination of HNO2 to afford a methylenecyclopentanone, also with excellent diastereoselectivity. The fifth pot involved a Michael reaction of vinyl cuprate. In the sixth pot, three reactions, a cis-selective olefin metathesis, diastereoselective reduction, and deprotection, afforded latanoprost. Nearly optically pure latanoprost was obtained, and the total yield was 24%.

Use of chiral auxiliaries in the asymmetric synthesis of biologically active compounds: A review

This review article describes the use of some of the most popular chiral auxiliaries in the asymmetric synthesis of biologically active compounds. Chiral auxiliaries derived from naturally occurring compounds, such as amino acids, carbohydrates, and terpenes, are considered essential tools for the construction of highly complex molecules. We highlight the auxiliaries of Evans, Corey, Yamada, Enders, Oppolzer, and Kunz, which led to remarkable progress in asymmetric synthesis in the last decades and continue to bring advances until the present day.

Access to a Key Building Block for the Prostaglandin Family via Stereocontrolled Organocatalytic Baeyer-Villiger Oxidation

A new protocol for the construction of a crucial bicyclic lactone of prostaglandins using a stereocontrolled organocatalytic Baeyer-Villiger (B-V) oxidation was developed. The key B-V oxidation of a racemic cyclobutanone derivative with aqueous hydrogen peroxide has enabled an early-stage construction of a bicyclic lactone skeleton in high enantiomeric excess (up to 95 %). The generated bicyclic lactone is fully primed with two desired stereocenters and enabled the synthesis of the entire family of prostaglandins according to Corey's route. Furthermore, the reactivity and enantioselectivity of B-V oxidation of racemic bicyclic cyclobutanones were evaluated and 90-99 % ee was obtained, representing one of the most efficient routes to chiral lactones. This study further facilitates the synthesis of prostaglandins and chiral lactone-containing natural products to promote drug discovery.

Enantio- and Diastereoselective Synthesis of Latanoprost using an Organocatalyst

An enantioselective total synthesis of latanoprost was achieved. Its chiral cyclopentane core structure was constructed through an organocatalyst-mediated [3+2]-cycloaddition reaction, and chirality in the ω-side chain was generated by prolinate-anion-mediated α-aminoxylation of an aldehyde. Highly diastereoselective domino acetalization and an oxy-Michael reaction were key steps for the generation of C9 chirality.