Toward a Total Synthesis of the Immunosuppressant Sanglifehrin A. Preparation of Two Relay Compounds by Degradation and Their Use in the Reassembly of the Natural Product

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• 作者：Rainer Metternich ; Donatienne Denni ; Binh Thai ; and Richard Sedrani
• 刊名：Journal of Organic Chemistry
• 出版年：1999
• 出版时间：December 24, 1999
• 年：1999
• 卷：64
• 期：26
• 页码：9632 - 9639
• 全文大小：161K
• 年卷期：v.64,no.26(December 24, 1999)
• ISSN：1520-6904

文摘

A potential relay route for the synthesis of the novel immunosuppressive agent sanglifehrin A (1)has been developed. Degradation of 1 by a sequence involving regioselective dihydroxylation of theC26,C27 double bond, followed by periodate cleavage of the resulting diol 4, afforded lactol 2 andmacrocyclic aldehyde 3. Intramolecular ketal formation between the 1,3-diol and ketone functionspresent in 3 gave ketal-aldehyde 5. Lactol 2 was converted into sulfone 14 in four steps. Thefragments 5 and 14 were reassembled, using the Julia-Kocienski olefination procedure, to affordintermediate 15, which was converted back to sanglifehrin A (1) after two deprotection steps.