The Preparation of 6-Bromo-3,4-dihydro-2H-pyrans from Tetrahydropyran-2-ones via a Ni(0)-catalysed Coupling Reaction and their Halogen-metal Exchange to 6-Lithio-3,4-dihydro-2H-pyrans.
作者:Jacqueline E. Milne、Krzysztof Jarowicki、Philip J. Kocienski
DOI:10.1055/s-2002-22698
日期:——
tetrahydropyran-2-ones undergo Ni(0)-catalysed substitution with LiBr to give the corresponding 6-bromo-3,4-dihydro-2H-pyr-ans under mild conditions. The 6-bromo-3,4-dihydro-2H-pyrans undergo halogen-metal exchange with tert-butyllithium to give the corresponding 6-lithio-3,4-dihydro-2H-pyrans.
由易于获得的四氢吡喃-2-酮制备的烯醇三氟甲磺酸酯衍生物在温和条件下经过 Ni(0)-催化的 LiBr 取代得到相应的 6-溴-3,4-二氢-2H-pyr-ans。6-溴-3,4-二氢-2H-吡喃与叔丁基锂进行卤素-金属交换,得到相应的6-锂硫-3,4-二氢-2H-吡喃。