Beilstein J. Org. Chem.2025,21, 2657–2693, doi:10.3762/bjoc.21.206
starting material was again the (S)-Wieland–Miescher ketone (34). This was transformed to nitrile 46 via a seven-step sequence consisting of protecting group manipulations, a double bond isomerization to position C5–C6, as well as a 1,2-cyanideaddition, and subsequent elimination (Scheme 10). The cyanide
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Graphical Abstract
Scheme 1:
Representatives of steroid alkaloid classes. Marked in blue is the steroidal cholestane framework, ...
Beilstein J. Org. Chem.2013,9, 832–837, doi:10.3762/bjoc.9.95
alcohol; amino aldehyde; azide addition; Baylis–Hillman reaction; cyanideaddition; Michael addition; Introduction
Nitroalkenes constitute a class of organic compounds that present exceptional versatility in organic synthesis [1][2][3][4]. They are reactive in Michael reactions with a wide variety of
reaction times were employed (Table 1, entries 4 and 5). On the other hand, a severe decrease in the diastereoselectivity occurred with longer durations, presumably due to an equilibration by a retro-conjugate addition [77] (Table 1, entries 6–8). Next, the conjugate cyanideaddition to 2a,b promoted by
addition of “HCN” equivalent to nitroalkenes is rare in the literature [78][79][80][81][82][83]. Paulsen [78] and Sakakibara [79] were the first authors to report the cyanideaddition to α,β-unsaturated nitroalkenes. In agreement with our results, Sakakibara [79] and Spanevello [80] observed a total or
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Graphical Abstract
Scheme 1:
Reagents and conditions: (i) K2CO3, EtOH/H2O 5:1, BnBr, 100 °C, 12 h (90–99%). (ii) (a) LiAlH4, THF...