反应详情

5 mmol of 2,2-dimethyl-5-[3-[(triphenylmethyl)thio]-propyl]-1,3-dioxane-5-propanoic-4,6-dione (I) (2.3 g), was dissolved with 20 mmol methyl-3-bromopropionate (3.34 g=2.18 ml) and 4.6 ml of 4.37 M methanolic solution of sodium methoxide (20 mmol) in 10 ml of methanol. The reaction mixture was heated to 60° C. overnight after which TLC in hexane/ethylacetate 1:1 detected no starting material. The mixture was then evaporated to dryness and mixed with 40 ml of aqueous 10% KHSO4. The organic material was extracted by 3 portions of EtOAc, the organic layers were combined dried with MgSO4 and evaporated. The residue was crystallized from hexane/ethylacetate to yield 2.1 g (77%) of 2,2-dimethyl-4,6-dioxo-5-[3-[(triphenylmethyl)thio]propyl]-1,3-dioxane-5-propanoic acid methyl ester (II), 13C-NMR (CDCl3) δ24.6, 29.4, 29.5, 29.6, 31.4, 32.6, 37.7, 51.9, 52.8, 66.8, 105.7, 126.7, 127.9, 129.5, 144.7, 168.4, 172.0.

1. customThe mixture was then evaporated to dryness
2. additionmixed with 40 ml of aqueous 10% KHSO4
3. extractionThe organic material was extracted by 3 portions of EtOAc
4. dry with materialthe organic layers were combined dried with MgSO4
5. customevaporated
6. customThe residue was crystallized from hexane/ethylacetate