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Scheme 4.16 Formation of bicyclo[5.3.0]decadienes via an allenic cyclocarbonylation reaction.
....................................................................................................................................................... 89
Scheme 4.17 Allenic cyclocarbonylation reaction toward the synthesis of guanacastepene A.... 90
Scheme 4.18 Attempted cyclocarbonylation reaction of 73f........................................................ 91
Scheme 4.19 Mechanism for the cycloisomerization and cyclocarbonylation reaction of 73f. ... 92
Scheme 4.20 Transfer of stereochemical information in the reaction of 73f................................ 97
Scheme 4.21 Cyclocarbonylation reaction of N-tosyl tethered allenyne 275............................... 98
Scheme 4.22 Cyclocarbonylation reaction of a terminally unsubstituted allene.......................... 99
Scheme 4.23 Structure of HMAF and key fulvene synthesis step.............................................. 100
Scheme 4.24 Synthesis of novel pentafulvenes. ......................................................................... 100
Scheme 4.25 Acid catalyzed polymerization of pentafulvenes. ................................................. 101
Scheme 4.26 Design of novel acyl-fulvenes............................................................................... 102
Scheme 4.27 Attempted cyclocarbonylation reactions of 145e.................................................. 102
Scheme 4.28 Selected cycloaddition reactions of fulvenes ........................................................ 103
Scheme 4.29 Mo-mediated cyclocarbonylation reactions of 73a and 73b................................. 104
Scheme 4.30 Cyclocarbonylation reaction of phenylalanine derived allenynes......................... 106
Scheme 4.31 X-ray crystal structure of 287b. ............................................................................ 106
Scheme 4.32 Cyclocarbonylation reaction of allenynes 74c, 74d and 74e. .............................. 107
Scheme 4.33 Isomerization of enones 287d, 287e and 288b. .................................................... 108
Scheme 4.34 Assignment of the relative stereochemistry of 287e and 288e based on NOESY
correlation spectrum.................................................................................................................... 109
Scheme 4.35 Ester assistance in the isomerization of 287e to 290e........................................... 109
Scheme 4.36 Ab initio energy calculations of α-methylene cyclopentenones 287b, 288b and
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