- The manufacture of a homochiral 4-silyloxycyclopentenone intermediate for the synthesis of prostaglandin analogues
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A process is described for the synthesis of kilogram quantities of homochiral 4-silyloxycyclopentenone (R)-1, a key intermediate useful for the synthesis of a plurality of prostaglandin analogue drugs. Cyclopentenone (R)-1 was synthesized in 14 isolated steps from furfural. Key steps in the synthesis include a Wittig reaction, Piancatelli rearrangement, and an enzymatic resolution featuring in situ recycling of the undesired enantiomer furnishing the desired homochiral alcohol in ≥99.5% ee. As a retort to the unsatisfactory coformation of about 8% at best of the trans-olefin in the Wittig reaction, a change to the order of several steps and the identification of a recrystallisable, amine salt derivative, 2, allowed the unwanted isomer to be controlled to as low as 0.2%.
- Henschke, Julian P.,Liu, Yuanlian,Huang, Xiaohong,Chen, Yungfa,Meng, Dechao,Xia, Lizhen,Wei, Xiuqiong,Xie, Aiping,Li, Danhong,Huang, Qiang,Sun, Ting,Wang, Juan,Gu, Xuebin,Huang, Xinyan,Wang, Longhu,Xiao, Jun,Qiu, Shenhai
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p. 1905 - 1916
(2013/03/13)
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- Process for the Preparation of Prostaglandin Analogues and Intermediates Thereof
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The present application provides intermediates for preparing prostaglandin analogues and processes for preparing prostaglandin analogues and intermediates thereof. The intermediates include: A compound of formula (6): R1 represents H, C1-C5-alkyl, or benzyl, in particular isopropyl.
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Page/Page column 15
(2009/10/21)
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