1: 92 percent / diisobutylaluminium hydride (DIBAL-H) / reduction 2: 1.) tricarbonyl(η6-arene)chromium(0) complex derived from (1R,2S)-N,N-dibutylnorephedrine, 2.)disibutylaluminium hydride (DIBAL-H) / 1.) toluene, hexanes, 0 deg C, 12 h, 2.) toluene, 23 deg C, 2 h View Scheme