2-Trimethylsilyl-1,3-propanediol

Abstract

[189066-36-2] C6H16O2Si (MW 148.2) InChI = 1S/C6H16O2Si/c1-9(2,3)6(4-7)5-8/h6-8H,4-5H2,1-3H3 InChIKey = BGMVXIDWBZLIRZ-UHFFFAOYSA-N (reagent for the protection of ketones and aldehydes under mild conditions1) Alternate Name: cyclo-SEM. Physical Data: mp 36–38 °C; bp 110–130 °C/2 mmHg. Solubility: soluble in organic solvents, insoluble in water. Form Supplied in: white, crystalline solid. Analysis of Reagent Purity: 1H NMR, capillary GC. Preparative Methods: preparation (eq 1) is performed by lithium–halogen exchange of 1-(bromovinyl)trimethylsilane 1,2 with 2.1 equiv of t-BuLi in diethyl ether at −78 °C for 0.5 h followed by cold cannulation into a slurry of paraformaldehyde in diethyl ether and warming to room temperature over 5 h.3 The crude 2-trimethylsilyl-2-propenol 2 is purified, after water work-up and extraction, by column chromatography (5% EtOAc/petroleum ether) followed by bulb-to-bulb distillation (110–114 °C/60 mmHg). Treatment of 2 with 2.1 equiv of freshly prepared thexylborane4 at −10 °C followed by 18 h at room temperature generates the boronate ester which is subsequently hydrolyzed by treatment with two equiv of methanol followed by a standard H2O2/NaOH work-up. Column chromatography on base-treated silica gel with 50% EtOAc/petroleum ether yields 2-trimethylsilyl-1,3-propanediol 3, as a white crystalline solid. (1) Purification: column chromatography using silica gel as the stationary phase and a mobile phase consisting of 50% EtOAc/petroleum ether will provide reagent of excellent quality. Recrystallization from either petroleum ether or hexanes, or bulb-to-bulb distillation (110–130 °C/2 mmHg) may also be used to purify the cyclo-SEM diol 2. Handling, Storage, and Precautions: store in a closed container. No noticeable degradation after 12 months on the bench top.