Synthesis of 6‐methoxy‐2,2‐dimethyl‐2<i>H</i>‐1‐benzothiopyran and 6,7‐dimethoxy‐2,2‐dimethyl‐2<i>H</i>‐1‐benzothiopyran, sulfur analogues of precocene I and precocene II

Abstract

Abstract Preparation of title compounds 5 , sulfur analogues of the natural insect antijuvenile hormones precocene I and II, is described. The synthetic pathway involves conversion of the appropriate thiophenol 2 into the corresponding thiochroman‐4‐one 4 followed by reduction and dehydration. The 13 C nmr data for all the above products are also reported.