Six-membered ring lactones (cont.)
N-heterocyclic carbene-catalyzed ring
expansion, 136
one-carbon ring enlargement, 134
one-step spiroannelation, 131
oxidative lactonization, 117–119
palladium-catalyzed lactonization, 128–129
radical cyclization, 127
samarium iodide-mediated reductive
cyclization, 127–128
selenolactonization, 124–125
Watt synthesis, 131, 132
Solanoeclepin, 165–166
(–)-Spinosyn A, 415
Spiramycin I, 398–399
5,6-and 6,6-Spiroacetals
[3+2]-cycloadditions, 245
[4+2]-cycloadditions
Ag(I)-catalyzed HDA cascade
approach, 241, 242
berkelic acid, 239, 241
bis(benzannulated) spiroacetals,
244, 245
Cu(I)-catalyzed cycloisomerization/
HDA cascade approach, 245
mono(benzannulated) spiroacetals,
242, 243
o-quinone methides, 239, 240
Pd-catalyzed HDA cascade approach,
239–241
cyclopropane ring-opening approaches,
257–259
dehydrative spirocyclization,
dihydroxyketone (see Dehydrative
spirocyclization)
DIHMA (see Double intramolecular
hetero-Michael addition (DIHMA))
electrophilic cyclization, 228–229
endocyclic enol ether (see Endocyclic
enol ether)
exocyclic enol ether, spirocyclization,
214–215
Goekjian approach, 214, 215
iodoetherification/Ag-catalyzed
cyclization, 215
sulfone lithiation approach, 216
furan oxidation strategies, 245–247
hemiacetal spirocyclization, 205, 206
auripyrones A and B, 206, 207
berkelic acid, 206, 208
Henryon and Fe ´re ´zou’s approach,
205, 206
pteridic acid A, 206, 207
intramolecular hydrogen abstraction,
247–252
bis(benzannulated) spiroacetals,
250, 251
cryptoacetalide and
danshenspiroketallactone, 250, 251
hippuristanol, 249
γ-rubromycin, 252
(benzannulated) 5,5-spiroacetals,
252, 253
transition states, 249
metal-catalyzed addition/elimination,
allylic alcohol, 203–205
Fe(III)-catalyzed spirocyclization,
204, 205
Pd-catalyzed spirocyclization,
203–205
Pd-catalyzed synthesis, 203, 204
oxa-Michael cyclization, 229
bis(benzannulated) spiroacetals,
230, 231
cascade approaches, 231
desymmetrization/oxa-Michael
addition, 230, 232
norhalichondrin B, 229, 230
rearrangements
anionic homo-fries rearrangement/
lactonization, 259–260
Ferrier, 260–262
rhenium-catalyzed allylic alcohol
rearrangement, 262
reductive cyclization methods, 252–253
ring-closing metathesis, 253, 255
aigialospirol, 255
bis(spiroacetals), 256, 257
papulacandin-like spiroacetals, 255
ring opening, of epoxide, 233
aryl substitution effect, 235, 237
carbohydrate-derived epoxides, 234
epoxidation–spirocyclization
method, 236
intramolecular epoxide ring-opening
reaction, 238
mono(benzannulated) spiroacetals,
235, 236
sawaranospirolides, 236, 237
transition metal-catalyzed intramolecular
hydroalkoxylation approach, 217
aliphatic bis(spiroacetals), 222
aliphatic spiroacetals, 218–222
Au(I)-catalyzed, 218
bis(benzannulated) spiroacetals,
225–228
438
Index
N-heterocyclic carbene-catalyzed ring
expansion, 136
one-carbon ring enlargement, 134
one-step spiroannelation, 131
oxidative lactonization, 117–119
palladium-catalyzed lactonization, 128–129
radical cyclization, 127
samarium iodide-mediated reductive
cyclization, 127–128
selenolactonization, 124–125
Watt synthesis, 131, 132
Solanoeclepin, 165–166
(–)-Spinosyn A, 415
Spiramycin I, 398–399
5,6-and 6,6-Spiroacetals
[3+2]-cycloadditions, 245
[4+2]-cycloadditions
Ag(I)-catalyzed HDA cascade
approach, 241, 242
berkelic acid, 239, 241
bis(benzannulated) spiroacetals,
244, 245
Cu(I)-catalyzed cycloisomerization/
HDA cascade approach, 245
mono(benzannulated) spiroacetals,
242, 243
o-quinone methides, 239, 240
Pd-catalyzed HDA cascade approach,
239–241
cyclopropane ring-opening approaches,
257–259
dehydrative spirocyclization,
dihydroxyketone (see Dehydrative
spirocyclization)
DIHMA (see Double intramolecular
hetero-Michael addition (DIHMA))
electrophilic cyclization, 228–229
endocyclic enol ether (see Endocyclic
enol ether)
exocyclic enol ether, spirocyclization,
214–215
Goekjian approach, 214, 215
iodoetherification/Ag-catalyzed
cyclization, 215
sulfone lithiation approach, 216
furan oxidation strategies, 245–247
hemiacetal spirocyclization, 205, 206
auripyrones A and B, 206, 207
berkelic acid, 206, 208
Henryon and Fe ´re ´zou’s approach,
205, 206
pteridic acid A, 206, 207
intramolecular hydrogen abstraction,
247–252
bis(benzannulated) spiroacetals,
250, 251
cryptoacetalide and
danshenspiroketallactone, 250, 251
hippuristanol, 249
γ-rubromycin, 252
(benzannulated) 5,5-spiroacetals,
252, 253
transition states, 249
metal-catalyzed addition/elimination,
allylic alcohol, 203–205
Fe(III)-catalyzed spirocyclization,
204, 205
Pd-catalyzed spirocyclization,
203–205
Pd-catalyzed synthesis, 203, 204
oxa-Michael cyclization, 229
bis(benzannulated) spiroacetals,
230, 231
cascade approaches, 231
desymmetrization/oxa-Michael
addition, 230, 232
norhalichondrin B, 229, 230
rearrangements
anionic homo-fries rearrangement/
lactonization, 259–260
Ferrier, 260–262
rhenium-catalyzed allylic alcohol
rearrangement, 262
reductive cyclization methods, 252–253
ring-closing metathesis, 253, 255
aigialospirol, 255
bis(spiroacetals), 256, 257
papulacandin-like spiroacetals, 255
ring opening, of epoxide, 233
aryl substitution effect, 235, 237
carbohydrate-derived epoxides, 234
epoxidation–spirocyclization
method, 236
intramolecular epoxide ring-opening
reaction, 238
mono(benzannulated) spiroacetals,
235, 236
sawaranospirolides, 236, 237
transition metal-catalyzed intramolecular
hydroalkoxylation approach, 217
aliphatic bis(spiroacetals), 222
aliphatic spiroacetals, 218–222
Au(I)-catalyzed, 218
bis(benzannulated) spiroacetals,
225–228
438
Index