Ring transformation of 4-acylmethyl-2-chloro-4-hydroxy-2-cyclobutenone to γ-acylmethylenetetronate by thermal rearrangement: New synthetic aspect of squaric acid as a C4-synthon
作者:Yoshihiko Yamamoto、Masatomi Ohno、Shoji Eguchi
DOI:10.1016/s0040-4020(01)85262-5
日期:1994.1
TiCl4-catalyzed addition of a silyl enol ether to squaric acid dichloride and ester chloride were subjected to thermolysis (reflux in an aromatic solvent), and γ -acylmethylenetetronates were obtained stereoselectively with (Z)-geometry via an α,β unsaturated chloroketene intermediate. The mechanism, application of this novel rearrangement to synthesis of basidalin and related photolysis were described