Substituent chemical shift (scs) values for the acetylation and mesylation
of hydroxy-p-benzoquinones and for the introduction of acetyloxy and mesylo
xy groups into p-benzoquinones were derived after complete C-13 NMR assignm
ent of all ring carbons for nine perezone derivatives and six thymoquinone
derivatives, which follow from one-bond and long-range multiplicities. Copy
right (C) 2000 John Wiley & Sons, Ltd.