-catalyzed reaction of (Z)-6-trimethylsilyl-5-hexen-1-ol with aldehydes gives trans2,3-disubstituted tetrahydropyrans (THPs) with high stereoselectivity (Scheme 1). 5 The reaction mechanism involves alkene migration of the vinylsilane and subsequent annulation of the resultant allylsilane with an aldehyde via an oxocarbenium ion intermediate. In view of the reactivity of oxocarbenium ions toward the ene-type
We developed a copper(II) triflate-bisphosphine complex catalyzed olefin migration and Prins cyclization which lead to the synthesis of substituted tetrahydropyran derivatives. The protocol is convenient and a variety of substituted tetrahydropyrans were obtained in good to excellent yields with excellent diastereoselectivities.
BADET, B.;JULIA, M.;MALLET, J. M.;SCHMITZ, C., TETRAHEDRON LETT., 1983, 24, N 40, 4331-4334
作者:BADET, B.、JULIA, M.、MALLET, J. M.、SCHMITZ, C.
DOI:——
日期:——
JOHNSTON, MADELINE I.;KWASS, JILL A.;BEAL, RICHARD B.;SNIDER, BARRY B., J. ORG. CHEM., 52,(1987) N 24, 5419-5424
作者:JOHNSTON, MADELINE I.、KWASS, JILL A.、BEAL, RICHARD B.、SNIDER, BARRY B.
DOI:——
日期:——
Stereochemical studies of type-II intramolecular ene reactions of .delta.,.epsilon.-unsaturated aldehydes
作者:Madeline I. Johnston、Jill A. Kwass、Richard B. Beal、Barry B. Snider