An asymmetric spiroorthocarbonate compound having one exomethylene group and represented by the following general formula (1) ##STR1## wherein A represents a group selected from the group consisting of: ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each represents a hydrogen atom, a lower alkyl group having not more than 8 carbon atoms, an alkoxy group, a halogen group, a nitro group, a cyano group, an amino group, an amide group, a hydroxyl group or an alkyl ester group having not more than 20 carbon atoms; and R.sup.5, R.sup.6, R.sup.7 and R.sup.8, R.sup.9 through R.sup.14, R.sup.15 through R.sup.22, R.sup.23 through R.sup.28 and R.sup.29 through R.sup.36 each represents a hydrogen atom or a lower alkyl group having not more than 8 carbon atoms; and copolymers containing units therefrom.