title: Phosphine-catalyzed synthesis of 1,3-dioxan-4-ylidenes.
abstract: [reaction: see text] A phosphine-catalyzed reaction of an allenoate with aldehydes furnished (2,6-diaryl-[1,3]dioxan-4-ylidene)-acetates 4 in excellent to moderate yields with complete diastereoselectivity and high E/Z-selectivities. Upon removal of the acetal functionality in this domino reaction product 4, delta-hydroxy-beta-ketoester 11 was obtained. The reported vinylphosphonium-based approach provides a new way to achieve a synthesis of delta-hydroxy-beta-ketoesters that differs from the classical dianion-based approach.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, USA.
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Zhu
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Henry
authors.forename: Jay
authors.initials: J
authors.lastname: Wang
authors.forename: Travis
authors.initials: T
authors.lastname: Dudding
authors.forename: Ohyun
authors.initials: O
authors.lastname: Kwon