A Modular Synthesis of 2-Alkyl- and 2-Arylchromans via a Three-Step Sequence
Robert K. Orr*, Louis-Charles Campeau, Harry R. Chobanian, Jamie M. McCabe Dunn, Barbara Pio, Christopher W. Plummer, Andrew Nolting, Rebecca T. Ruck
*Department of Process Chemistry, Merck Research Laboratories, 126 E Lincoln Ave, Rahway, NJ 07065, USA, Email: robert.orrmerck.com
R. K. Orr, L.-C. Campeau, H. R. Chobanian, H. M. McCabe Dunn, B. Pio, C. W. Plummer, A. Nolting, R. T. Ruck, Synthesis, 2017, 49, 657-666.
DOI: 10.1055/s-0036-1588075 (free Supporting Information)
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A convergent three-step method provides 2-substituted chromans via Heck coupling of readily accessible allylic alcohols and 2-iodophenols, followed by reduction and Mitsunobu cyclization. The utility and generality of this method is demonstrated through the synthesis of a series of 2-aryl-, 2-heteroaryl- and 2-alkylchromans, as well as an azachroman derivative. A Noyori-catalyzed ketone reduction enables an asymmetric version.
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