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Synthesis of (4 R ,5 S )‐Melithiazols F and I
Author(s) -
Takayama Hiroyuki,
Kato Keisuke,
Akita Hiroyuki
Publication year - 2006
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200500568
Subject(s) - chemistry , wittig reaction , aldehyde , phosphonium , trimethylsilyl , phytophthora capsici , stereochemistry , amide , lithium (medication) , iodide , natural product , medicinal chemistry , organic chemistry , catalysis , pepper , food science , medicine , endocrinology
Palladium‐catalyzed cyclization‐methoxycarbonylation of (2 R ,3 S )‐3‐methylpenta‐4‐yne‐1,2‐diol ( 8 ) derived from the (2 R ,3 S )‐epoxybutanoate 7 followed by methylation gave the tetrahydro‐2‐furylidene acetate (–)‐ 9 , which was converted into the left‐half aldehyde (+)‐ 4 . A Wittig reaction between (+)‐ 4 and the phosphoranylide derived from the bithiazole‐type phosphonium iodide 5 using lithium bis(trimethylsilyl)amide afforded (+)‐(4 R ,5 S )‐melithiazol F ( 1 ), whose spectroscopic data were identical with those of the natural product 1 . Moreover, the synthesis of (+)‐(4 R ,5 S )‐melithiazol I ( 2 ), was achieved by the same synthetic strategy as that of (+)‐(4 R ,5 S )‐melithiazol F ( 1 ). The antifungal activity of the synthetic melithiazols F ( 1 ) and I ( 2 ) against the phytopathogenic fungus, Phytophthora capsici , was evaluated by using a paper disc assay method.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)