Tetrahedron

BiBr 3 initiated cyclization–addition reactions: effect of π-nucleophile on oxocarbenium ion addition and total syntheses of (+)-(S, S)-(cis-6-methyltetrahydropyran-2-yl) …

…, Y Lian, ND Litvinas, AT Jenkins, DC Burnette

Index: Hinkle, Robert J.; Lian, Yajing; Litvinas, Nichole D.; Jenkins, Alex T.; Burnette, Daniel C. Tetrahedron, 2005 , vol. 61, # 49 p. 11679 - 11685

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Citation Number: 17

Abstract

For BiBr3 initiated tandem cyclization–additions of very reactive silyl ketene acetal nucleophiles with δ-silyloxy aldehydes to afford 2, 6-disubstituted THP products, diastereoselectivities range from 5–6: 1 (trans-/cis-). The selectivity for axial attack on the intermediate oxocarbenium ion is inversely proportional to π-nucleophilicity. We have utilized this chemistry to convert a common starting material to both cis-and trans- ...