Enantio- and diastereoselective aldol reactions of achiral ethyl and methyl ketones with aldehydes: the use of enol diisopinocampheylborinates

New Boronic-Acid- and Boronate-Substituted Aromatic Compounds as Precursors of Fluoride-Responsive Conjugated Polymer Films

“…[15] Thus, 3-vinyl- [16] (4a) and 3-allylthiophene [17] (4b) were treated with diisopinocampheylborane [18] (Ipc 2 BH), previously prepared from (ϩ)-α-pinene and boraneϪdimethyl sulfide, to give the diethyl boronate derivatives (Scheme 1). Treatment with aqueous acid or pinacol yielded 5a and 6a؊b, respectively, in 22Ϫ26% overall yield.…”

“…It was prepared from (ϩ)-α-pinene and boraneϪdimethyl sulfide according to a known procedure. [18] 4a and 4b were synthesized in two steps in yields of 70% and 40% from 3-(2-hydroxyethyl)-thiophene and 3-bromothiophene, respectively, according to previously described procedures. [16,17] 7 was prepared in 55% overall yield from pyrrole.…”

The antibody catalysis route to the total synthesis of epothilones

“…At this point, the reaction was interrupted and purified from the aldehyde to give a pure, kinetically resolved product. The absolute structure of the remaining compound after retro-aldol reaction was identified as (ϩ)-syn-5 by a comparison with the synthetic sample of (ϩ)-syn-5 † (61).…”

Total Synthesis of Entecavir

“…14 As shown in Scheme 2, the in situ reduction of the resulting chelate 15 with LiBH 4 followed by an oxidative work up provided 3a…”

“…A solution of 13 (6.300 g, 12.94 mmol) in formic acid 80% (126 mL) at 50 ºC under N 2 was stirred for 9 h. The solvent was removed, H 2 O (72 mL) was added and the suspension was stirred for 18 h at rt. The suspension was filtered and the solid was dried to afford the title compound (14) as a yellow solid (5.590 g, 92% 9, 164.3, 156.8, 153.5, 151.2, 150.3, 147.8, 136.1, 135.1, 130.7, 123.9, 116.5, 111.2, 74.1, 65.6, 55.2, 47.8, 35.2, 21.0 …”