Stereoselective preparation of (Z)-2-(trialkylsilyloxy)-2-alkenals by retrocycloaddition reactions of 4H-4-Alkyl-5-(trialkylsilyloxy)-1,3-dioxins. Useful reactants for Lewis acid catalyzed [4 + 3] cyclizations.
[reaction: see text]. Retrocycloadditions of 4H-4-alkyl-5-(trialkylsilyloxy)-1,3-dioxins proceed smoothly in refluxing toluene to afford (Z)-2-(trialkylsilyloxy)-2-alkenals with complete stereoselectivity. These enals undergo Sasaki-type [4 + 3] cyclizations with dienes in the presence of Lewis acids, in many instances with excellent regio- and/or stereoselectivity.
Aungst
R A
RA
Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Funk
R L
RL
D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D004147:Dioxins / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D013237:Stereoisomerism
D000475:Alkenes; D004147:Dioxins; D012833:Siloxanes