Acid-catalyzed ring expansion of 1-(1-methoxy-1,2-propadienyl)-2-cyclobuten-1-ols. Synthesis of 5-hydroxy-5-vinyl-2-cyclopenten-1-ones and their stereoselective transformation to 5-(2-acetoxyethylidene)-2-cyclopenten-1-ones
Acid-catalyzed ring expansion of 1-(1-methoxy-1,2-propadienyl)-2-cyclobuten-1-ols. Synthesis of 5-hydroxy-5-vinyl-2-cyclopenten-1-ones and their stereoselective transformation to 5-(2-acetoxyethylidene)-2-cyclopenten-1-ones