American Chemical Society
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Total Synthesis of (−)-Solanapyrone A via Enzymatic Diels−Alder Reaction of Prosolanapyrone

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journal contribution
posted on 1998-11-10, 00:00 authored by Hideaki Oikawa, Tomonori Kobayashi, Kinya Katayama, Yuichi Suzuki, Akitami Ichihara
The syntheses of prosolanapyrones I (6) and II (7) via the aldol reactions of pyrone and dienal segments have been achieved in five steps in 31% overall yield for 6 and seven steps in 5% overall yield for 7. An improved synthetic route starting from vinylpyrone 27 provided 7 in 11 steps in 12% overall yield. The enzymatic Diels−Alder reaction of 7 affords (−)-solanapyrone A (1) with high enantioselectivity and with good exo-selectivity, which is difficult to attain by chemical methods. In addition, a crude enzyme preparation from Alternaria solani has been used to perform a kinetic resolution of (±)-3.