Synthesis of the common left-half part of pectenotoxins

Synthetic studies towards the pectenotoxins: a review

“…3). 21 The key step in this synthesis involves selective generation of an a-lithiated tetrahydrofuran 23 from the corresponding phenylthioacetal 20 (Scheme 1). 22 Tetrahydrofuran 20, which contains the correct stereochemistry, was synthesised as a mixture of stereoisomers from alcohol 19 23 in 5 steps whilst the aldehyde fragment 22 was synthesised from epoxy alcohol 21 24 in 4 steps (Scheme 1).…”

Diastereoselective Synthesis of the Pectenotoxin 2 Non-Anomeric AB Spiroacetal

“…Evans completed the first and only syntheses of pectenotoxin macrolides, PTX-4 and PTX-8, in 2002 . Many other research groups have described approaches to fragments of pectenotoxin, including Murai, Roush, Brimble, and Paquette . Of particular relevance to the current report, Pihko reported the synthesis of the AB spiroacetal segment of PTX-2 by a kinetic cyclization .…”

Pectenotoxin-2 Synthetic Studies. 3. Assessment of the Capacity for Stereocontrolled Cyclization To Form the Entire C1−C26 Subunit Based upon the Double Bond Geometry Across C15-C16

“…In light of the above, there have understandably been a number of efforts targeting several PTXs. Among the more notable achievements to date are Evans' asymmetric synthesis of pectenotoxins-4 and -8, Brimble's targeting of the ABC segment of PTX7, and Roush's preparation of the C11−C26 fragment of PTX2, in addition to Murai's successful routes to the C8−C18 and C31−C40 components common to all members. − Our approach to the synthesis of 1 is based on the convergent coupling of either sulfonyl tetrazole 4 11 or phosphonium iodide 5 to aldehyde 6 . These key disconnections are illustrated in Scheme .…”