Gómez-Reino Clara, Vitale Cristian, Maestro Miguel, Mouriño Antonio
Departamento de Química Orgánica y Unidad Asociada al CSIC, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
Org Lett. 2005 Dec 22;7(26):5885-7. doi: 10.1021/ol052489c.
[reaction: see text] A mild palladium-catalyzed cascade has been used for the synthesis of the hormone 1alpha,25-dihydroxyvitamin D3 (calcitriol, 1a) and its analogues 1b and 1c. This one-pot process involves two consecutive transformations at room temperature: An initial palladium-catalyzed 6-exo-cyclocarbopalladation of vinyl triflates followed by a Negishi cross-coupling reaction with an alkenyl zinc. This novel strategy opens new possibilities for the preparation of a variety of new vitamin D analogues of therapeutic potential, particularly with modifications at the triene and/or ring-A.
[反应：见正文] 一种温和的钯催化串联反应已用于合成激素1α,25-二羟基维生素D3（骨化三醇，1a）及其类似物1b和1c。这个一锅法过程在室温下涉及两个连续的转化：首先是钯催化的乙烯基三氟甲磺酸酯的6-外向环碳钯化反应，接着是与烯基锌的根岸交叉偶联反应。这种新策略为制备具有治疗潜力的各种新型维生素D类似物开辟了新的可能性，特别是在三烯和/或A环处进行修饰的类似物。
