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A short, formal, biomimetic synthesis of (+/-)-polygalolides A and B.

ABSTRACT: [reaction: see text] Reaction of bisacetoxy pyranone 9 with Et3N gave 3-oxidopyrylium ylide 10, which underwent a stereo- and regiospecific [5 + 2] cycloaddition with alpha-methylenebutyrolactone to afford 16 (34%). Treatment of 16 with Cs2CO3 resulted in hydrolysis of the lactone and acetate and conjugate addition of the hydroxyethyl group to the enone. Lactonization on acidification afforded 4 (57%), completing a two-step, formal synthesis of polygalolides A and B.

SUBMITTER: Snider BB

PROVIDER: S-EPMC2532947 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature

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A short, formal, biomimetic synthesis of (+/-)-polygalolides A and B.

Snider Barry B BB Wu Xiaoxing X Nakamura Seiichi S Hashimoto Shunichi S

Organic letters 20070201 5

[reaction: see text] Reaction of bisacetoxy pyranone 9 with Et3N gave 3-oxidopyrylium ylide 10, which underwent a stereo- and regiospecific [5 + 2] cycloaddition with alpha-methylenebutyrolactone to afford 16 (34%). Treatment of 16 with Cs2CO3 resulted in hydrolysis of the lactone and acetate and conjugate addition of the hydroxyethyl group to the enone. Lactonization on acidification afforded 4 (57%), completing a two-step, formal synthesis of polygalolides A and B. ...[more]

PMID: 17266323

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