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Unified synthesis of C19-C26 subunits of amphidinolides B1, B2, and B3 by exploiting unexpected stereochemical differences in Crimmins' and Evans' aldol reactions.

ABSTRACT: The efficient synthesis of the C(19)-C(26) subunit of amphidinolide B(1) and B(2) has been completed using a boron-mediated aldol reaction. The synthesis of the C(19)-C(26) subunit of amphidinolide B(3) has also been accomplished through an unexpected anti aldol reaction using a titanium-mediated process. In addition, the first reported examples of a stereochemical discrepancy between the Evans' boron-mediated oxazolidinone and the Crimmins' titanium-mediated oxazolidinethione aldol reactions are disclosed. A working hypothesis is put forth to explain the results.

SUBMITTER: Zhang W

PROVIDER: S-EPMC2430272 | biostudies-literature | 2004 Apr

REPOSITORIES: biostudies-literature

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Unified synthesis of C19-C26 subunits of amphidinolides B1, B2, and B3 by exploiting unexpected stereochemical differences in Crimmins' and Evans' aldol reactions.

Zhang Wei W Carter Rich G RG Yokochi Alexandre F T AF

The Journal of organic chemistry 20040401 7

The efficient synthesis of the C(19)-C(26) subunit of amphidinolide B(1) and B(2) has been completed using a boron-mediated aldol reaction. The synthesis of the C(19)-C(26) subunit of amphidinolide B(3) has also been accomplished through an unexpected anti aldol reaction using a titanium-mediated process. In addition, the first reported examples of a stereochemical discrepancy between the Evans' boron-mediated oxazolidinone and the Crimmins' titanium-mediated oxazolidinethione aldol reactions ar ...[more]

PMID: 15049660

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