Stereoselective construction of 3a-methylhydrindanes starting from 2, 7-enynol derivatives based on Ti (II)-mediated cyclization and Ru-catalyzed ring-closing …
The Ti (II)-mediated cyclization of 3-methyloct-2-en-7-yn-1-ol derivatives 2 proceeded stereoselectively to afford 1-methyl-2-(1-alkylbut-3-enylidene)-1-vinylcyclopentanes 3 after treatment of the resulting alkenyltitaniums with allylbromide in the presence of CuCN, which was readily converted to 3a-methyl-2, 3, 3a, 6-tetrahydro-1H-indenes 1 by the Ru-catalyzed ring-closing metathesis.
