B. Diab et al., ONE-STEP SYNTHESIS OF A NEW CLASS OF METHANODIBENZO-[B,F][1,5]DIOXOCINES STARTING FROM FLAVYLIUM SALTS, Journal of chemical research. Synopses, (12), 1994, pp. 456-457
Reduction of 4-methyl-2-(o-hydroxyaryl)benzopyrylium chlorides with so
dium borohydride in acetonitrile at pH ca. 3 affords methanodibenzo[b,
f][1,5]dioxocine derivatives in good yields; the structure of one diox
ocine was confirmed by X-ray analysis.