2007

Ring closure reactionsO 0130 Site-Specific Preparation of 2-Carboalkoxy-4-substituted Naphthalenes and

9-Alkylphenanthrenes and Evidence for an Allene Intermediate in the Novel Base-Catalyzed Cyclization of 2-Alkynylbiphenyls. — The title reaction affords a variety of substituted naphthalene or phenanthrene derivatives in moderate to high yields. In the case of (XIII), the type of product [(XIV) vs. (XV)] depends on the reac-tion time. Evidence is presented that allenes play a role as intermediates. — (WANG, Y.; BURTON*, D. J.; Org. Lett. 8 (2006) 23, 5295-5298; Dep. Chem., Univ. Iowa, Iowa City, IA 52242, USA; Eng.) — R. Steudel

12- 031

2007