Synthesis of β-Alkoxycyclic Ethers from ω-Organometallic Ether Acetals. Stereocontrol with the Combined Lewis Acid System, Titanium(IV) Chloride-Triphenylphosphine

Abstract
The titanium(IV) chloride-triphenylphosphine mediated intramolecular cyclization of γ-oxo-substituted allylic silane 1 (4-[3-(trimethylsilyl)-1- propenyloxy]butanal propylene acetal) having an acetal group at the terminus of the carbon chain produced the 6-membered trans isomer 2a [trans-3-(3-hydroxypropoxy)-2-vinyltetrahydropyran] with very high diastereoselectivity in high yield. Highly stereoselective synthesis of seven- and eight-membered rings was also accomplished by the use of titanium(IV) chloride-triphenylphosphine.

This publication has 0 references indexed in Scilit: