Synthesis of Drim-9(11)-en-8α- and -8β-ols from Drimenol
作者:K. I. Kuchkova、A. N. Aryku、I. P. Dragalin、P. F. Vlad
DOI:10.1007/s10600-005-0109-8
日期:2005.3
Drim-9(11)-en-8α-ol and drim-9(11)-en-8β-ol were synthesized in six steps from drimenol. Drimenol was oxidized by P2O5 and DMSO to drimenal, which isomerized with p-TsOH into isodrimenal. Isodrimenal was reduced by NaBH4 into isodrimenol, epoxidation of which by m-CPBA gave a mixture (3.4:1) of α- and β-epoxyisodrimenols. These reacted with tosyl chloride in Py to give a mixture of α- and β-epoxyisodrimenol tosylates. Treatment of the tosylate mixture with KI and then Ph3P produced a mixture of drim-9(11)-en-8α- and -8β-ols that was separated chromatographically. The overall yield was ∼26%.
Enantiospecific, Biosynthetically Inspired Formal Total Synthesis of (+)-Liphagal
作者:Jonathan H. George、Jack E. Baldwin、Robert M. Adlington
DOI:10.1021/ol100756z
日期:2010.5.21
A biosynthetically inspired synthesis of (+)-liphagal has been achieved from (+)-sclareolide in 13 steps (9% overall yield). The key step is a biomimetic ring expansion of a highly stabilized benzylic carbocation, which generates the seven-membered ring and the benzofuran of the natural product in a single cascade reaction.
Further Synthetic Studies Towards the Austrodorane Skeleton: Synthesis of Austrodoral
The synthesis of austrodoral (1), a marine nor-sesquiterpene that contains a unique bicyclic skeleton, has been achieved. The synthetic strategy is based on the ring contraction of a suitable optically active drimanic epoxy derivative, obtained from commercially available (+)-sclareolide (4). Fluorosulfonic acid was found to promote the ring contraction efficiently. The nor-sesquiterpene hydrocarbon
Synthesis and absolute configuration of drim-9(11)-en-8-ols from Aspergillus oryzae
作者:Gema Domínguez、Juan A. Hueso-Rodríguez、María C. de la Torre、Benjamín Rodríguez
DOI:10.1016/s0040-4039(00)92302-5
日期:1991.1
An enantiomeric synthesis of the drimane sesquiterpenes 1 and 2has been achieved starting from the diterpene (+)-royleanone (3) via its derivative 5. This result establishes that the natural sesquiterpenes isolated from Aspergillus oryzae have a normal absolute stereochemistry, like steroids. This conclusion is opposite to other data recently published.