The Total Synthesis of Dihydrocostunolide

Corey, E. J.; Hortmann, Alfred G.

doi:10.1021/ja00952a037

Cited by 88 publications

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“…(+)--Eudesmol 3 was ob tained af ter elim i na tion of the ha lide of com pound 11 with LiBr-LiCO 3 /DMF in high yield (90%). 7 Con se quently, epoxidation of 3 with m-CPBA, in the pres ence of NaHCO 3 , af forded 3 ,4 -epoxide 12 stereoselectively. The last step in the syn the sis of the ti tle com pound 1 was to bring the regioselective re ar range ment of epoxide 12 to an al lyl ic al co hol moi ety.…”

Section: Re Sults and Discussionmentioning

confidence: 99%

An Efficient Synthetic Strategy for Introduction of C₃‐C₄ Double Bond into Eudesmane Skeleton: First Total Synthesis of (+)‐Chrysanthemol

Chen

Zhou

Xiong

et al. 2001

J Chinese Chemical Soc

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The first enantioselective syn the sis of (+)-chrysanthemol 1 was car ried out start ing from (+)-dihydrocarvone in ten steps. In our stud ies, a fac ile syn thetic strat egy has been de vel oped for in t ro duc tion of C3-C4 dou ble bond into a eudesmane skel e ton. IN TRO DUC TION Chry san the mum indicum L1 is a tra di tional Chi nese med i cine com monly used. It ex hib its con sid er able bi o log i cal ac tiv i ties such as antipyretion, de tox i fi ca tion, and re duc ing blood pres sure. Re cently, a clin i cal study has in di cated that Chry san the mum indicum L has fairly good ef fects on chronic pel vic carity in flam ma tion, pel vic carity tu ber cu lo sis and pros trate gland in flam ma tion. A pharmacodynamics study dem on strates that it can re sist bac te ria, con trol blood platelet ag gre ga tion, ex pand cor o nary, and re duce blood pres sure. In 1987, Yu and Xie iso lated (+)-chrysanthemol 1 from the flower of Chry san the mum indicum L and elu ci dated its struc ture on the ba sis of spec tral and chem i cal ev i dence.1 At the same time, El-Ghazouly and co-workers iso lated sesquiterpene -xylopyranosides 2 and 4 from the ae rial parts of Iphiona scarbra. 2 Herein we de scribe the first to tal syn the sis of (+)-chrysanthemol 1 start ing from (+)-dihydrocarvone in ten steps. In our syn the sis, the nat u ral prod uct (+)--eudesmol was also ob tained as a key in ter me di ate. 3 RE SULTS AND DIS CUS SIONIn our syn thetic strat egy, a dou ble bond at the C-3, C-4 po si tion is pref er a ble. Pre vi ously, there have been many attempts for the in tro duc tion of C-3, C-4 dou ble bond in a eudesmane skel e ton.4 Sev eral of these meth ods have been applied for the syn the sis of eudesmol. But it is im prac ti cal to ap ply these meth ods in the syn the sis of the eudesma acid functionalized at C-3, C-4 due to some draw backs. These short com ings en tail de vel op ing a more ef fi cient syn thetic route to in tro duce a dou ble bond into a eudesmane skel e ton. In this pa per we also pro vided an ef fi cient, con ve nient syn thetic ap proach to wards the in tro duc tion of C3-C4 dou ble bond into a eudesmane skel e ton. Em ploying this strat egy, we com pleted the to tal syn the sis of (+)-chrysanthemol 1 as shown in the fol low ing scheme.By the pub lished method, 5 ( )--cyperone 6 was eas ily pre pared from (+)-dihydrocarvone 5 in 50% yield. Lith iumliquid am mo nia re duc tion of 6, us ing am mo nium chlo ride as the pro ton do nor, af forded the dihydro--cyperone 7 stereospecificly. 4a Uti lizing the steric hin drance of 10 -methyl, stereoselective re duc tion of 7 by tri-t-butoxyaluminium hydride gave al co hol 8 in high yield. By a stereospecific manner, al co hol 8 was con verted into its 3 -chloro de riv a tive 9 by PPh 3 -NCS in THF un der mild con di tions. 6 Epoxidation of 9 with m-CPBA, fol lowed by LiAlH4 re duc tion af forded alco hol 11. (+)--Eudesmol 3 was ob tained af ter elim i na tion of the ha lide of com pound 11 with LiBr-LiCO 3 /DMF in high yield (90%). 7 Con se quentl...

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Section: Re Sults and Discussionmentioning

confidence: 99%

An Efficient Synthetic Strategy for Introduction of C₃‐C₄ Double Bond into Eudesmane Skeleton: First Total Synthesis of (+)‐Chrysanthemol

Chen

Zhou

Xiong

et al. 2001

J Chinese Chemical Soc

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“…7 Elimination of the halide of 11 with LiBr-LiCO 3 in DMF gave compound 12 in 86% yield. 8 Following the published procedure, 6 allylic aldehyde 12 was oxidized with AgNO 3 at ambient temperature and gave the acid 1 in 60% yield eventually. The spectral data of the synthetic product 1 are identical with those of natural product.…”

Section: Methodsmentioning

confidence: 99%

Enantioselective Total Synthesis of Eudesma-3,11(13)-dien-12-oic Acid

Chen¹,

Zhou²,

Liu³

et al. 2001

Synthesis

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“…[33,49,67] E. J. Corey and his graduate student Alfred Hortmann (Figure 13) published severala lternating stereospecific reactions in 1963 (as ac ommunication [68] )a nd in 1965 (as af ull paper) (Figure 14). [69] Corey and Hortmann's reactions were strong hints that ar evolution in mechanistic understanding was forthcoming. That both the Woodward and Corey groups were workingo nt he total synthesis of an atural product combinedw ith the chronological coincidence of Ranganathan'sa nd Hortmann's experiments, the geographical coincidenceo ft heir professional locations (both at Harvard'sD epartment of Chemistry), the experimentalc oincidence of their reactions (thermala nd photochemical six-electron electrocyclizations), and the analytical coincidence of their structure determinations ( 1 HNMR spectroscopy,l ikely run on the exact same Varian A-60 spectrometer), all together render ac omparison of their results of historical importance and ac hemical curiosity worth documenting.…”

Section: Simultaneous But Independente Lectrocyclization Reactions and Structural Assignments By Corey And Hortmannmentioning

confidence: 99%

On the Structural Assignments Underlying R. B. Woodward's Most Personal Data That Led to the Woodward–Hoffmann Rules: Subramania Ranganathan's Key Role and Related Research by E. J. Corey and A. G. Hortmann

Tantillo

Seeman

2021

Chemistry A European J

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In the early 1960s, as part of R. B. Woodward's isoxazole route to vitaminB 12 ,S ubramania Ranganathan uncovered two coupled sets of stereospecific reactions, at hermal set and ap hotochemicals et. These four reactions illustrated the alternatingc onfigurations that were the majord ata points that prompted the solution of the no-mechanism problem. Though Ranganathan's reactions played am ajor role, according to Woodward,i nt he development of the Woodward-Hoffmann rules, they were published only as part of the documentation of al ectureg iven by Woodward in 1966. The authors of this paper have uncovered Subramania Ranganathan's 1964 postdoctoral report and have used modern quantum chemical theory to predict the 1 HNMR spectra for Ranganathan's key compounds, providing support for the structure assignments madeb yW oodward and Ranganathan. As imilar set of alternating, stereospecific reactions was observed by E. J. Corey and Alfred Hortmann in their 1963t otal synthesis of dihydrocostunolide. We also have applied the computational process used for Ranganathan'sc ompounds to Hortmann's compounds, now also includingt he calculationo fc oupling constants, and find computational support for Coreya nd Hortmann's structure assignments.

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The Total Synthesis of Dihydrocostunolide

Cited by 88 publications

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An Efficient Synthetic Strategy for Introduction of C₃‐C₄ Double Bond into Eudesmane Skeleton: First Total Synthesis of (+)‐Chrysanthemol

An Efficient Synthetic Strategy for Introduction of C₃‐C₄ Double Bond into Eudesmane Skeleton: First Total Synthesis of (+)‐Chrysanthemol

Enantioselective Total Synthesis of Eudesma-3,11(13)-dien-12-oic Acid

On the Structural Assignments Underlying R. B. Woodward's Most Personal Data That Led to the Woodward–Hoffmann Rules: Subramania Ranganathan's Key Role and Related Research by E. J. Corey and A. G. Hortmann

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The Total Synthesis of Dihydrocostunolide

Cited by 88 publications

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An Efficient Synthetic Strategy for Introduction of C3‐C4 Double Bond into Eudesmane Skeleton: First Total Synthesis of (+)‐Chrysanthemol

An Efficient Synthetic Strategy for Introduction of C3‐C4 Double Bond into Eudesmane Skeleton: First Total Synthesis of (+)‐Chrysanthemol

Enantioselective Total Synthesis of Eudesma-3,11(13)-dien-12-oic Acid

On the Structural Assignments Underlying R. B. Woodward's Most Personal Data That Led to the Woodward–Hoffmann Rules: Subramania Ranganathan's Key Role and Related Research by E. J. Corey and A. G. Hortmann

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An Efficient Synthetic Strategy for Introduction of C₃‐C₄ Double Bond into Eudesmane Skeleton: First Total Synthesis of (+)‐Chrysanthemol

An Efficient Synthetic Strategy for Introduction of C₃‐C₄ Double Bond into Eudesmane Skeleton: First Total Synthesis of (+)‐Chrysanthemol