Ein neuer Zugang zu Spiroorthocarbonaten und neuen Orthokohlensäure-Derivaten
作者:Peter Mues、Hans-Josef Buysch
DOI:10.1055/s-1990-26845
日期:——
A New Approach to Spiroorthocarbonates and New Orthocarbonic Acid Derivatives New and simple processes have been developed, which give in good or excellent yields new diphenoxyalkanediyldioxymethanes, symmetrical and unsymmetrical spiroorthocarbonates, spirocyclic orthothiocarbamic acid esters, and acetals of urea by successive or simultaneous substitution of chloro and phenoxy groups contained in dichlorodiphenoxymethane.
Hydrolysis of Spiro Derivatives that Undergo No Shrinkage on Polymerization
作者:Hirotaka Tagoshi、Takeshi Endo
DOI:10.1246/bcsj.62.945
日期:1989.3
Acid-catalyzed hydrolyses of spiroorthoeters (1, 2a, 2b, and 2c) and spiroorthocarbonates (3 and 4) were carried out to give the corresponding ring-opening reaction products. The ring-cleavage modes of these spiro derivatives depended on the structure of intermediate cations.
or NaBH4–NiCl2 as the key steps. Further, the latter title compound was prepared effectively through the reaction of 3-O-benzylsulfonyl-5-O-(4-deoxy-4-iodomycaminosyl)-23-O-(dimethylthexylsilyl)tylonolide 9,20-bis(ethylene acetal) with Raney Ni–K2CO3 involing three steps in it.