Oxidative and hydrolytic cleavage of cyclopropane and spirocyclobutane derivatives of 6,8-dioxabicyclo[3.2.1]octane,the products of transformation of levoglucosenone

A new method for the synthesis of (1R,4S,5S)-4-hydroxymethyl-3-oxabicyclo3.1.0]hexan2-one, the cyclopropane analog of (S)-5-hydroxypent-2-en-4-olide, has been suggested based on oxidation of (1S,2S,4R,6R)-7,9-dioxatricyclo4.2.1.0^2,4]nonan-5-one. Oxidation of cyclobutanones, spirojoined with the fragments of 6,8-dioxabicyclo3.2.1]oct-2-ene, 6,8-dioxabicyclo3.2.1]octane (at position 4), or 7,9-dioxatricyclo4.2.1.0^2,4]nonane (at position 5), upon the action of m-chloroperoxybenzoic acid or the KMnO₄-H₂SO₄-H₂O system leads to the corresponding spirojoined butanolides in 73–85% yields. The same cyclobutanones easily undergo the four-membered ring opening upon the action of dilute H₂SO₄ at 50–90 °C to form 6,8-dioxabicyclo3.2.1]octane-4- or 7,9-dioxatricyclo4.2.1.0^2,4]nonane-5-propionic acid.