ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Synthesis of Two Naturally Occurring 10-Membered Ring Lactones: (±)-Phoracantholide J and ITwo 10-membered ring lactones 7 and 11 from the metasternal secretion of the eucalypt longicorn Phoracantha synonyma have been synthesized by the following method. Reaction of the dilithium derivative of 4-pentynoic acid (3) with 4-tetrahydropyranyloxy-1-pentylbromide (2), followed by removal of the protecting group and by esterification with diazomethane, gave methyl 9-hydroxy-4-decynoate (4; s. Scheme 1). Partial hydrogenation of the triple bond in 4 with Lindlar palladium catalyst, followed by saponification lead to cis-9-hydroxy-4-decenoic acid (6). The 9-hydroxydecanoic acid (9) was synthesized by addition of methyl magnesium iodide to methyl 8-formyloctanoate (8) followed by saponification (s. Scheme 2). The hydroxy acids 6 and 9 were converted into the S-(2-pyridyl) thioesters and cyclized in dilute benzene solution under the influence of silver ions to yield (±)-phoracantholide J (7) and I (11) in 74 and 71% yield, respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19780610404
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