161062-83-5Relevant academic research and scientific papers
Preparation and Cationic Rearrangements of ortho- and para-Methoxy-TADDOLs
Seebach, D.,Rheiner, P.B.,Beck, A.K.,Kuehnle, F.N.M.,Jaun, B.
, p. 2397 - 2414 (2007/10/02)
(R,R)-α,α,α',α'-Tetra(2-methoxy- and 4-methoxyphenyl)-1,3-dioxolane- and -2,2-dimethyl-1,3-dioxolane-4,5-dimethanols are prepared from the corresponding tartrate acetal or ketal and Grignard reagents.The ortho-methoxy derivatives have an unusual conformation in the crystalline state (determined by X-ray analysis) and in solution (derived from chiroptical measurements).Structural similarities with the TADDOL bearing six phenyl groups are discussed, and the crystal structure of a hydrogen-bonded clathrate of this TADDOL with piperidine is also reported.Under acidicconditions the 4-methoxy-TDDOLs undergo cyclisation to a tetrahydrofuran or to a dihydro-naphthalene derivative, which in turn rearranges to 6-methoxy-1,3,4-tris(4-methoxyphenyl)naphth-2-yl acetate.The structures of these TADDOL "decomposition" products are proved by NMR and X-ray analysis.Wagner-Meerwein rearrangement, aromatization, carbocations, X-ray structure of chiral ligands, TADDOLs, - new methoxy derivatives, - crystal structure, - NMR analysis, optical comparison and conformation of TADDOLs
