71276-94-3Relevant articles and documents
CONTROLLED FORMATION OF DIPYRANOSIDE DERIVATIVES THROUGH C6 AND 04. PYRANOSIDIC HOMOLOGATION. VII
Molino, Bruce Francis,Fraser-Reid, Bert
, p. 2834 - 2842 (2007/10/02)
A procedure has been developed for pyranosidic homologation of methyl α-D-glucopyranoside via C4 and C6.Reaction of the aldehydo group of compound 2 with the Wittig-Bestmann reagent, Ph3P=CHCH(OEt)2, gave an E/Z mixture of acetals, 4, which cyclizes under
Cumulated Ylides, XII. A Stereoselective Synthetic Method for (Z)-α,β-Unsaturated Aldehydes
Bestmann, Hans Juergen,Roth, Kurt,Ettlinger, Manfred
, p. 161 - 171 (2007/10/02)
(2-Ethoxyvinyl)triphenylphosphonium bromide (5) is converted with sodium amide into the corresponding phosphaallenylide 6 which adds ethanol forming the ylide 7. 7 is also obtained by the reaction of 5 with sodium ethanolate.The Wittig reaction of 7 with aldehydes 2 proceeds with high (Z)-stereoselectivity to give (Z)-α,β-unsaturated acetals 8 which are cleaved under well defined conditions with p-toluenesulfonic acid or with wet silica gel to (Z)-α,β-unsaturated aldehydes 9.
