摘要:
The carbonylolefination of the title alkoxy aldehydes by 2-thiazolecarbonylmethylenetriphenyl-phosphorane 3 affords the corresponding (E)-enones which undergo syn-diastereoselective (ds, 85-95%) 1,4-conjugate addition of benzyl oxide anion; acid-catalyzed methanolysis of polyalkoxyalkyl ketones obtained in that way gives methyl 1-(2-thiazolyl)pyranoside precursors to ulosonic acids.