Ethylaluminium dichloride induced reactions of acetals with unsaturated carboxylic esters: Synthesis of homoallyl ethers

The ethylaluminium dichloride induced reactions of methyl 10-undecenoate (1) with dimethyl acetals of formaldehyde 2a, acetaldehyde 2b, isobutyraldehyde 2c, and pivaldehyde 2d gave the corresponding homoallyl ethers 3a, 3b, 3c, and 3d in yields of 48-70%. The products were obtained as mixtures of the (E) and (Z) stereoisomers. With formaldehyde dimethyl acetal (2a), methyl oleate (6), and methyl petroselinate (11) gave the corresponding regioisomeric (E)-configured homoallyl ethers 7/8 and 12/13.