The influence of a resident stereocenter on the formation of hydropero
xy acetals from carbonyl oxides is investigated. Addition of either me
thanol or 2-propanol to 8-phenylpropanal O-oxide proceeds with modest
stereoselectivity; addition of a tertiary alcohol proceeds with higher
selectivity. Product stereochemistry, which is confirmed by conversio
n of a functionalized hydroperoxy acetal to a 1,2-dioxane, is found to
derive from nucleophilic attack through a Felkin-Anh type transition
state. Trapping of a carbonyl oxide containing a neighboring hydrogen
bond donor proceeds with modest selectivity for both syn- and anti-car
bonyl oxide isomers. Ozonolysis of a 3-(trialkylstannyl)-1-enol ether
proceeds with loss of the stannyl-bearing carbon through the possible
intermediacy of a vinyl peroxide.