Efficient and practical method for synthesizing optically active indan-2-ols by the Ti(O-i-Pr)(4)/2 i-PrMgCl-mediated metalative Reppe reaction.

An efficient and practical synthesis of optically active indan-2-ols 1 has been developed starting from readily accessible optically active 4-siloxy-1,6-alkadiynes 2 and ethynyl p-tolyl sulfone, where the metalative Reppe reaction mediated by an economical divalent titanium reagent, Ti(O-i-Pr)(4)/2 i-PrMgCl, is a key step.