4-deoxy-4-sulfo-D-erythrose <=> 4-deoxy-4-sulfo-D-erythrulose
4-deoxy-4-sulfo-d-erythrose <=> 4-deoxy-4-sulfo-d-erythrulose
4-deoxy-4-sulfo-D-erythrose <=> 4-deoxy-4-sulfo-D-erythrulose
4-deoxy-4-sulfo-d-erythrose <=> 4-deoxy-4-sulfo-d-erythrulose