Page 1. SYNTHETIC COMMUNICATIONS, 26(9), 1729-1738 (1996) ... 1729 Copyright 0 1996 by Marcel Dekker, Inc. Page 2. 1730 ... The hydroxy-acetal 1 was converted to the naphtho[2,3-b]dioxin system (3 or 4 ) by treatment with p - toluenesulfonic acid or acetic acid and, the ...