Synthesis of enantiopure 2,7-diaryl-1,6-dioxaspiro[4.4]nonanes via enantioselective reduction of prochiral γ-nitroketones by diisopinocampheylchloroborane (DIP-Cl(TM))

Article abstract of DOI:10.1016/0957-4166(96)00232-7

The enantioselective reduction of γ-nitroketones 1-4 and γ-nitrodiketones 5-6 by the chiral reducing agent (+)- or (-)-diisopinocampheylchloroborane (DIP-Cl(TM)) afforded respectively nitroalcohols 7-9 with e.e's ranging from 33 to 86% and nitrodiols 11-12 with complete diastereoselectivity and e.e. > 95%. Nitrodiols (1S,7S)-11 and (1S,7S)-12 were then used as chiral precursors for the synthesis of the enantiopure 2,7-diphenyl- and 2,7-di-(2'-methoxyphenyl)-2,6-dioxaspiro[4.4]nonanes, 21 and 22, as EE/ZZ mixtures.