Base catalysed rearrangement of a spiro oxy-cope system and related studies

Syntheses and biological studies of marine terpenoids derived from inorganic cyanide

“…In a final example, Vanderwal attempts to form the all- trans tricyclic core of the amphilectenes and adocianes via a transannular Michael reaction, lxv according to the report by Swaminathan that 105 is formed preferentially from 104 . lxvi Vanderwal determined that 105 was misassigned, and the Michael reaction instead produces 106 and 107 , which contain stable, mixed cis - and trans -decalin motifs, as proven by X-ray analysis. Furthermore, 106 and 107 are kinetic traps; their attempted equilibration does not lead to 105 .…”

Recent advances in the synthesis of natural multifunctionalized decalins

“…Scheme 16 Corey's total synthesis of dehydroabietic acid. Corey has recently reported that the 1 : 1 complex of o,o 0dichloro-R-BINOL and SbCl 5 (66) is able to initiate the enantioselective cationic polycyclization of polyunsaturated substrates at a predictable p-bond which may be either terminal or internal. 42,43 This strategy depends on the modulation of the relative proton affinity of the p-bonds within the substrate to control the initiating site of cyclization.…”

“…Exposure of (AE)-136 to This journal is © The Royal Society of Chemistry 2015 basic methanol results in a kinetic transannular conjugate addition to give diastereomers (AE)-137 and (AE)-138, both bearing a cis ring fusion (Scheme 33). 66 Angular 6-6-6 tricyclic systems are frequently encountered in polycyclic terpenoids and other natural products. While a number of strategies exist to synthesize such motifs, the transannular Michael reaction cascade proved to be particularly effective.…”

Progress in the Construction of Cyclooctanoid Systems: New Approaches and Applications to Natural Product Syntheses

“…Early examples of the synthesis of fused cyclooctanoid systems through the oxy-Cope processes ( 226 → 227 ) and ( 228 → 229 ) were reported by Swaminathan et al and by Gadwood et al, respectively. The latter workers have further elaborated the bicyclo[6.3.0]undecadienone 229 to the sesquiterpenoids poitediol and dactylol .…”