The Synthetic Routes of 3'H-CYCLOPROPA[1,2]PREGNA-1,4,6-TRIENE-3,20-DIONE

The synthesis of 3'H-CYCLOPROPA[1,2]PREGNA-1,4,6-TRIENE-3,20-DIONE, also known as cyclopenta[b]indene, is an important synthetic route in the chemical industry.
This compound is used in a variety of applications, including as a precursor to other organic compounds and as a building block for materials science.

There are several synthetic routes that can be used to synthesize cyclopenta[b]indene.
One of the most common methods is the Pinnick reaction, which involves the reaction of a substituted indole with a Grignard reagent followed by hydrogenation to form the cyclopenta[b]indene ring.
Another method involves the use of a alkynyl Grignard reagent, which undergoes a series of reactions to form the final product.

Another route to cyclopenta[b]indene is through the use of a Suzuki-Miyaura cross-coupling reaction, which involves the reaction of a boronic acid derivative with a aryl halide in the presence of a palladium catalyst.
This method is highly efficient and allows for the synthesis of a wide range of substituted cyclopenta[b]indenes.

One of the key advantages of the Suzuki-Miyaura cross-coupling reaction is that it does not require the use of a protecting group, which can make the synthesis of cyclopenta[b]indene more efficient and cost-effective.
Additionally, this method allows for the synthesis of substituted cyclopenta[b]indenes with high selectivity and the product can be easily purified by simple chromatographic techniques.

Another route to cyclopenta[b]indene is through the use of a tandem reaction, in which a substituted indole is first converted to a substituted α,β-unsaturated carbonyl compound using a Pinnick reaction, followed by hydrogenation to form the final product.

One of the main advantages of the tandem reaction is that it allows for the synthesis of cyclopenta[b]indene using less expensive starting materials, such as substituted indoles.

In conclusion, the synthesis of cyclopenta[b]indene is an important synthetic route in the chemical industry, with several different methods available to synthesize this compound.
The Pinnick reaction, alkynyl Grignard reaction, and Suzuki-Miyaura cross-coupling reaction are all effective methods for synthesizing cyclopenta[b]indene, and each has its own advantages and disadvantages.
Additionally, the use of a tandem reaction can also be an effective way to synthesize cyclopenta[b]indene using less expensive starting materials.
Regardless of the method used, the synthesis of cyclopenta[b]indene is an important step in the production of a variety of organic compounds and materials.