Divergent Synthesis of Six Recent Berkeleylactones

Asymmetric total syntheses of aspilactonol F and aspiketolactonol and synthetic studies toward diplofuranoxin

The first asymmetric total synthesis of C9 polyketides, aspilactonol F and aspiketolactonol has been achieved. Ring-closing-metathesis has been employed as the key step in the synthesis. The total synthesis of aspilactonol F and aspiketolactonol was accomplished in 8 and 10 steps, in good overall yields of 28% and 24%, respectively, with only four column purifications for the former. A common strategy for the concise synthesis of the key intermediate of diplofuranoxin is also presented.

Total Synthesis and Determination of the Absolute Configuration of Berkeleylactone I

Herein, we report the first total synthesis of berkeleylactone I and its 12S diastereomer. Consequently, this chemical synthesis allowed us to establish the unknown absolute stereochemistry at the C-12 center as 12R, which was unidentified by the isolation group. This synthetic approach includes several critical reactions, such as the Sharpless asymmetric dihydroxylation, Baran's Ni-catalyzed alkyl-alkyl cross-coupling reaction, Brown allylation, Mitsunobu reaction, and ring-closing metathesis, as key steps.

Steglich esterification: A versatile synthetic approach toward the synthesis of natural products, their analogues/derivatives

The exploitation of natural products and their analogues in the field of pharmacology has been regarded as of great importance. It can be attributed to the fact that these scaffolds exhibit diverse chemical properties, distinct biological activities and zenith specificity in their biochemical processes, enabling them to act as favorable structures for lead compounds. The synthesis of natural products has been a crafty and hard-to-achieve task. Steglich esterification reaction has played a significant role in that area. It is a mild and efficient technique for constructing ester linkages. This technique involves the establishment of ester moiety via a carbodiimide-based condensation of a carboxylic acid with an alcohol, thiol or an amine catalyzed by dimethyl aminopyridine (DMAP). Specifically, labile reagents with multiple reactive sites are esterified efficiently with the classical and modified Steglich esterification conditions, which accounts for their synthetic utility. This review encloses the performance of the Steglich esterification reaction in forging the ester linkage for executing the total synthesis of natural products and their derivatives since 2018.