(4R-cis)-6-formaldehydel-2,2-dimethyl-1, 3-dioxane-4-acetic acid,1,1-dimethylethyl ester CAS No.: 124752-23-4 (4R-cis)-6-甲醛基-2,2二甲基-1,3-二氧六环-4-乙酸叔丁酯