PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: XIX. CYCLIC ACETALS AND KETALS DERIVED FROM LEVO-2,3-BUTANEDIOL

Optically active 4,5-dimethyl-1,3-dioxacyclopentane derivatives can be easily obtained by condensing levo-2,3-butanediol with aldehydes or ketones in the presence of small amounts of strong acids at ordinary temperatures. Condensations were effected with formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, 2-ethylbutyraldehyde, 2-ethylhexaldehyde, benzaldehyde, furfural, acrolein, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, diethyl ketone, acetophenone, cyclohexanone, acetoin, and diacetyl. The expected products were obtained, two compounds being formed from diacetyl since one or both carbonyl groups may react. Two compounds were obtained from formaldehyde also; in addition to the expected product (levo-4,5-dimethyl-1,3-dioxacyclopentane), 15 to 20% of levo-6,7-dimethyl-1,3,5-trioxacycloheptane was obtained.