Highly diastereoselective additions of methoxyallene and acetylenes to chiral α-keto amidesElectronic supplementary information (ESI) available: synthesis and spectroscopic data for 4b, 5g, 6b and 7b. See http://www.rsc.org/suppdata/cc/b1/b100355k/
Abstract
α-Keto amides bearing (S)-indoline chiral auxiliaries reacted with lithiated methoxyallene or lithium acetylides to produce the corresponding dihydrofuranones 7 through formation of the tertiary α-hydroxy allenes, or tertiary α-hydroxy acetylenes, respectively, at −78 °C with high diastereoselectivities (up to >99% de).