With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.1194-16-7,2,2-Dimethyltetrahydropyran-4-one,as a common compound, the synthetic route is as follows.
A solution of 2,2-dimethyltetrahydropyran-4-one (133) (115 g, 0.9 mol, 1.0 eq.) in anhydrous THF (600 mL) was cooled to -78 C and to it was added LDA (2.0 M, 538 mL, 1.08 mol, 1.2 eq.) drop wise under N2 keeping the internal temperature below -65 C. The resulting solution was stirred at -78 C for 20 min. A solution of N-phenyl- bis(trifluoromethanesulfonimide) (353 g, 0.99 mol, 1.1 eq.) in anhydrous THF (1900 mL) was added to the above solution slowly keeping the internal temperature below -65 C. The reaction mixture was warmed to room temperature slowly and stirred overnight. The reaction was quenched with saturated aqueous sodium bicarbonate solution, and extracted with MTBE (2 L X 2). The combined organic layers was washed with 10% aqueous NaOH solution (1 L X 2), brine (500 mL X 2), dried over Na2S04, filtered and concentrated to give crude title triflate product mixture as dark brown oil. The crude product was extracted with hexanes (2 L X 5) and the combined hexanes extracts was purified by column chromatography (directly loaded onto silica gel, Hexanes? 15% ethyl acetate in hexanes, R/= 0.6, visualized with KMn04 stain) to give 200 g of the triflate product mixture (134) (a mixture of 2,2-dimethyl-3,6-dihydro-2H-pyran-4-yl trifluoromethanesulfonate and 6,6-dimethyl-3 ,6-dihydro-2H-pyran-4-yltrifluoromethanesulfonate ratio = 80.6: 19.4 by GCMS) as a light yellow liquid (~ 90% purity by GC-MS and 1H NMR). This was taken to the next step without further purification.
1194-16-7, 1194-16-7 2,2-Dimethyltetrahydropyran-4-one 1738159, aTetrahydropyrans compound, is more and more widely used in various fields.
Reference£º
Patent; AMGEN INC.; ALLEN, Jennifer R.; CHEN, Jian J.; FROHN, Michael J.; HU, Essa; LIU, Qingyian; PICKRELL, Alexander J.; RUMFELT, Shannon; RZASA, Robert M.; ZHONG, Wenge; WO2011/143365; (2011); A1;,
Tetrahydropyran – Wikipedia
Tetrahydropyran – an overview | ScienceDirect Topics