69285-46-7

Upstream product

• 923-42-2 butane-1,2,4-tricarboxylic acid 
• 4339-27-9 1,2,4-butanetricarboxylic acid trimethyl ester 
• 14267-92-6 1-chloro-4-pentyne 
• 1002-37-5 6-chloro-2-hexyn-1-ol 
• 81159-11-7 trans-2,3-bis(methoxycarbonyl)cyclopentanone 
• 69285-47-8 7-hydroxy-5-heptynenitrile 
• 77493-17-5 6-cyanohex-2-ynyl mesylate 
• 81159-29-7 trans-2-(benzyloxycarbonyl)-3-(methoxycarbonyl)cyclopentanone 

Relevant academic research and scientific papers

Prostaglandins. 3. Synthetic Approaches to 11-Deoxyprostaglandins

A straightforward synthesis is described of dl-trans-2--3-formylcyclopentanone (5), a versatile intermediate for the sythesis of 11-deoxyprostaglandins and their analogues.Base-catalyzed cyclization of 1,2,4-tris(methoxycarbonyl)butane under kinetically controlled conditions led to (70percent) trans-2,3-bis(methoxycarbonyl)cyclopentanone (3).Treatment of 3 with hot benzyl alcohol gave (80percent) trans-2-(benzyloxycarbonyl)-3-(methoxycarbonyl)cyclopentanone (25), which was purified as its copper chelate.Alkylation of 25 with 6-cyanohex-2-ynol mesylate (20) with NaH/dimethoxyethane afforded 82percent 2-(6-cyanohex-2-ynyl)-2-(benzyloxycarbonyl)-3-(methoxycarbonyl)cyclopentanone (26).Catalytic reduction of 26 in ethanol/pyridine, using a Pd/BaSO4 catalyst followed by warming, gave (91.5percent) a 9:1 mixture of trans-2-(6-cyanohex-2(Z)-enyl)-3-(methoxycarbonyl)cyclopentanone (27) and its 2,3-dihydro derivative 29.Chromatography of the corresponding carboxylic acids gave the pure acid 30 (69percent from 26).Reduction (NaBH4) of the acid chloride (31) of acid 30 led to a mixture of diols 32.Saponification of the nitrile group of 32 afforded the C-1 epimeric mixture of the diol acids 33, which on CH2N2 esterification (69percent from 31) and Collins oxidation afforded (92percent) the desired 5.A second route to 5 also was explored.Cyclization (t-BuOK/t-BuOH) of 4-tetrahydrofuran-2-one (12) led to cis-hexahydro-1H-cyclopentafuran-1,6-dione (4), which when alkylated (t-BuOK/t-BuOH) with 20 gave (90percent) the C-6a alkylation product 35.Alkaline saponification of 35 led to trans-2-(6-cyanohex-2-ynyl)-3-(hydroxymethyl)cyclopentanone (36) in only modest yield (15percent).A four-step sequence of catalytic reduction, nitrile hydrolysis, acid esterification, and oxidation then gave 5, in 44percent overall yield from 36.

Synthesis of 11-deoxyprostaglandins

Improved procedures and intermediates for synthesizing 11-deoxyprostaglandins wherein trans-2,3-dicarbomethoxycyclopentanone is prepared by the novel kinetically-controlled cyclization of 1,2,4-tricarbomethoxybutane using a dispersion of sodium hydride in