Synthesis and absolute configuration of optically active E-1-alkoxymethoxy-but-2-eny(tri-n-butyl)stannanes: stereoselective reactions with aldehydes

(1R)- and (1S)-1-[(–)-menthoxymethoxy]-E-but-2-enyl(tri-n-butyl)stannanes(5) and (6), whose configurations at C(1) were assigned by correlation with (2R)-and (2S)-pentan-2-ol, react stereoselectively on heating with benzaldeyde to give (3S,4R)- and (3R, 4R)-4hydroxy-3-methyl-cis-1,2-enol ethers (11) and (13), respectively.