117642-29-2Relevant academic research and scientific papers
CHEMISTRY OF KETENE ACETALS. PART 9. A SIMPLE 'ONE-POT' SYNTHESIS OF 4-HYDROXY-δ-LACTONES AND 5,6-DIHYDRO-2-PYRONES FROM 1,1-DIMETHOXYPROPENE AND β-OXY ALDEHYDES
Hofstraat, Rob G.,Lange, Jos,Scheeren, Hans W.,Nivard, Rutger J.F.
, p. 2315 - 2322 (2007/10/02)
Protected β-oxy aldehydes react easily with 1,1-dimethoxypropene (1a) in the presence of ZnCl2 to give 2,2-dimethoxyoxetanes.Hydrolysis of these oxetanes and deprotection of the latent hydroxy function in a one-pot procedure gives 4-hydroxy-δ-lactones in moderate to good yields.Starting with β-oxy aldehydes having an α-branched side chain and defined stereochemistry, δ-lactones with completely defined stereochemistry can be synthesized.Dehydration of the hydroxy lactones with concentrated sulphuric acid gives easy access to 5,6-dihydro-2-pyrones.The usefulness of this route is demonstrated in the synthesis of a simple, optically active 5,6-dihydro-2-pyrone (37).
