End game strategies towards the total synthesis of vibsanin E, 3-hydroxyvibsanin E, furanovibsanin A, and 3-O-methylfuranovibsanin A

• Brett D. Schwartz,
• Craig M. Williams and
• Paul V. Bernhardt

Beilstein J. Org. Chem. 2008, 4, No. 34, doi:10.3762/bjoc.4.34

• sidechain and corresponding α-oxo functionality depicted in Scheme 2. Essentially four areas were identified for study; 1) regio- and stereospecific α-hydroxylation (methoxylation) 19, 2) furan formation i.e. 20, 3) installing the acetone sidechain i.e. 21, and 4) building the enol ester function i.e. 22

• (Scheme 2). The results of each area of investigation allow end game strategies to be postulated based on combinations of these results. For example, success with α-hydroxylation (methoxylation) 19 could flow into furan formation (i.e. 20), installing the acetone sidechain i.e. 21, or building the enol

• cleavage. Nevertheless, the acetone sidechain could be introduced in ~20% overall yield allowing end game functionalisation (as discussed below). α-Hydroxylation was next investigated. Considering the observed preference for regiospecific enolate formation in our system we devised a simple two pot

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

• protection of the alcohol, MoO5-mediated hydroxylation of the enolate of the ester [22] and ensuing dehydration by SOCl2 (Scheme 2). The sequence utilized for the introduction of the dienophilic subunit in 13 is outlined in Scheme 3. The primary alcohol was deprotected (TBAF) and oxidized to an aldehyde