Total Synthesis and Determination of the Absolute Configuration of 5,6-Dihydro-α-pyrone Natural Product Synargentolide B

Enantiospecific
total synthesis and determination of the absolute
stereochemistry of the α-pyrone-containing natural product synargentolide
B were accomplished. The absolute stereochemistry of the natural product
was established by synthesizing the possible diastereomers and comparison
of the data with those reported for the natural product. During the
process, total synthesis of the putative structure of related natural
product 6R-[1S,2R,5R,6S-(tetraacetyloxy)-3E-heptenyl]-5,6-dihydro-2H-pyran-2-one
was also accomplished and confirmed by X-ray crystal structure analysis.
Wittig–Horner reaction of a chiral phosphonate derived from
(S)-lactic acid and ring-closing metathesis were
the key reactions during the course of the total synthesis.