Molecular Crystals and Liquid Crystals, Vol.431, 357-362, 2005
Photochromic naphthopyrans containing a latent carbene unit
3-(Hydroxyalkyl)-1-naphthols 12 have been accessed in two steps from an isoquinolinium salt. The naphthopyrans 15, derived from 12, were readily diazoacylated with ethyl diazomalonyl chloride. The carbenoid generated from 16 failed to undergo any cycloaddition and was instead intercepted by water to afford 18.