Page 1340 - Advanced Organic Chemistry Part B - Reactions & Synthesis

pK values Quinodimethanes 1317
table of, 3 as dienes in Diels-Alder reaction, 489–490, 501
Polar substituent effects Quinones Index
in aldol reactions, 96, 105–106 as dienophiles in Diels-Alder reaction, 494,
Polyamines 506–507, 512, 517
enolate reactivity, effect on, 20–21
Polyene cyclization, 864–869 Radicals
examples, 868 addition to alkenes, 956, 959–966
of squalene in steroid biosynthesis, 867 by allylic silanes, 961, 965–966
Polyenes by allylic stannanes, 963, 964, 965–966
preparation by Pd-catalyzed cross-coupling, 733 examples, 963–966
Polypeptide synthesis mechanism, 960–961
cyclic, 1243–1245 substituent effects, 960–962
solid phase, 1246–1250 addition to carbon-nitrogen double bonds, 973
coupling reagents for, 1248–1250 alkoxyl, generation from nitrites, 990
Fmoc protocol for, 1247–1248 aryl
linker groups for, 1248 addition to alkenes, 1035
t-Boc protocol for, 1246 aromatic substitution by, 1052
Potassium hexamethyldisilazide (KHMDS) from N-nitroso anilides, 1053
base for enolate formation, 5 as reaction intermediates, 956–992
Potassium tris-(1-methylpropyl) borohydride cyclization of, 967–990
as reducing agent, 399–400 ring size effects, 967–969
Prelog-Djerassi lactone, multistep synthesis of, tandem with alkylation, 979–981
1196–1209 1,4-di- as intermediates in
chiral auxiliaries in, 1205–1207 photocycloaddition, 548
1,5-diene hydroboration in, 1198 fragmentation of, 984–988
enzymatic desymmetrization in, 1200, 1202 alkoxyl, 988–986, 992
from carbohydrates, 1202–1203 cyclopropylmethyl, 986, 987
from meso-3,4-dimethylglutaric acid derivatives, generation from, 959, 961
1199–1202 boranes, 958–959
using enantioselective catalysis, 1207–1208 -cyano acids, 962
Proline N-hydroxypyridine-2-thiones, 957–958
enantioselective catalysis of aldol reaction, -keto acids, 962
131–133 malonic acids, 962
enantioselective catalysis of Mannich reaction, organomercury compounds, 959, 961–962
142–143 selenides, 958, 961, 963, 975
enantioselective catalysis of robinson annulation, thiono esters, 961, 963, 978
138–139 xanthates, 965, 972
Protective groups, 258–276, 1163, 1166 hexenyl, cyclization, 295,423,569, 621–622
alcohols, 258–265 hydrogen abstraction, 957, 960
amides, 271 intramolecular, 989–991
amines, 267–272 silanes, 961
carbonyl compounds, 274–275 stannanes, 961, 963
carboxylic acids, 274–275 iodine atom transfer, 970, 972, 974
Pseudoephedrine rearrangement of, 984, 985–986
chiral auxiliary in aldol reaction, 114–116 substituent effects on, 960–962
chiral auxiliary in enolate alkylation, 42 Ramberg-Backlund reaction, 895–898
Pyridazines, as Diels-Alder, dienes, 595 RAMP, see
Pyridine derivatives (R -N-amino2-methoxymethylpyrrolidine
nucleophilic aromatic substitution in, 1037 Red-Al, see sodium bis-(2-methoxyethoxy)
Pyridine-2-thiol esters aluminum hydride
acylation of alcohols by, 243 Reduction
2-pyridyl disulfide by diimide, 388–390
macroloactonization by, 249 by dissolving metals, 434–444
Pyrones by hydride donors, 396–429
as dienes in Diels-Alder reactions, by hydrogenation, 368–387
490–491, 1041 by hydrogen atom donors, 431–434
in synthesis of Baccatin III, 1212 Reductive amination, 403–404, 467