Gold(I)-catalyzed synthesis of γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with alcohols

• Michel Chiarucci,
• Mirko Locritani,
• Gianpiero Cera and
• Marco Bandini

Beilstein J. Org. Chem. 2011, 7, 1198–1204, doi:10.3762/bjoc.7.139

• synthesis of such a class of heterocyclic compounds has been the subject of several investigations. Among them, a multi-step synthetic pathway with final TBAF-promoted cyclization was proposed by Lepore [38] and, almost simultaneously, Poli and Prestat described a Pd-catalyzed Tsuji–Trost-type allylic

Sordarin, an antifungal agent with a unique mode of action

• Huan Liang

Beilstein J. Org. Chem. 2008, 4, No. 31, doi:10.3762/bjoc.4.31

• sordarin [17] in 2004 and 2006, respectively. Both Kato’s and Mander’s syntheses employed intramolecular Diels-Alder cyclizations to construct the norbornene-like framework, while an intramolecular Pd catalyzed Tsuji-Trost reaction was utilized by the Narasaka group to build the diterpene core. Kato’s

• reaction of sordaricin ester 34 with glycosyl fluoride 35. Unlike previous syntheses, the present one utilized an intramolecular Tsuji-Trost reaction [29] of allylic carbonate 37 to build the core of sordaricin 36. In turn, compound 37 was prepared from bicyclic ketone 38, which was derived from

• ). Selective cleavage of the TBS group and PCC oxidation surrendered ketone 49. Diastereoselective addition of vinylmagnesium chloride and exchange of the enol protecting group gave allylic alcohol 50. The substrate 51 for the Tsuji-Trost reaction was prepared by carbethoxylation of the allylic alcohol and