New Access to dl-Paniculide A Using α-Phenylthio-β-Vinylbutenolide as Synthetic Block

Article abstract of DOI:10.1016/S0040-4020(01)87730-9

A new synthetic approach to dl-paniculide A (1) based on the annulation of 2-formylpropionate with α-phenylthio-β-vinylbutenolide 4 is described.The annulation products 6a-6c was dehydrated to give 7, and the sulfoxide of 7 was submitted to sulfoxide-sulfinate rearrangement in aqueous media to yield 8a and 8b.The latter was converted to the former by configurational inversion of its hydroxyl group.Saturated lactone 11a obtained from 8a was homoprenylated, and after desilylation, the product 12b was selenenylated to give 13a.Alkaline hydrolysis followed by oxidative elimination of the selenenyl group provided 14a, which was then acetylated and oxidized with lead tetraacetate to yield 15a and 16a-16c. dl-Panaculide A was derived from 15a and 16a via 18a.