A FACILE TOTAL SYNTHESIS OF (±)-SELINA-3,11-DIEN-9-OL

Ａ　ＦＡＣＩＬＥ　ＴＯＴＡＬ　ＳＹＮＴＨＥＳＩＳ　ＯＦ　（±）－ＳＥＬＩＮＡ－３，　１１－ＤＩＥＮ－９－ＯＬＡＦＡＣＩＬＥＴＯＴＡＬＳＹＮＴＨＥＳＩＳＯＦ（±）－ＳＥＬＩＮＡ－３，１１－ＤＩＥＮ－９－ＯＬＬｉＪｕｎＬＩＵ；ＺｈａｏＭｉｎｇＸＩＯＮＧ；...     

A FACILE SYNTHESIS OF 1.2-BISPYRROLEETHYLENS

1. 2-Bispyrroleethylenes can be easily syntnesized bv cc,-,pt}ngpyrrolealdehyde using TiCl_4/Zn as a catalyst. It was found that when theR group is COMe or CO_2 Et, the product is a mixture of trans and cisisomers, and in the other cases, the products are pure trans isomers.     

TOTAL SYNTHESIS OF (±)TANIKOLIDE

ABSTRACT

A total synthesis of (±)tanikolide 1 is described. The six-membered lactone moiety of the title compound was completed through oxidation of α,δ-dihydroxyl compound by PDC.     

A FACILE SYNTHESIS OF 2-AND 2,4-UNSATURATED AMIDES

A convenient method for preparing unsaturated amides via telluro-nium salts employing solid potassium carbonate as a base with high stereo-selectivity in excellent yields has been developed.     

A FACILE TOTAL SYNTHESIS OF 6-PENTYL-α-PYRONE

ＡＦＡＣＩＬＥＴＯＴＡＬＳＹＮＴＨＥＳＩＳＯＦ６－ＰＥＮＴＹＬ－α－ＰＹＲＯＮＥ￥ＣｈｉＺＨＡＮＧ；ＸｕｅＣｈａｏＷＡＮＧ；ＦａｎｇＮｉｎｇＺＨＡＮＧａｎｄＸｉｎＦｕＰＡＮ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏ...     

A CONVENIENT PREPARATION OF 1,2,3,4,5,6,7,8-OCTAHYDRO-NAPHTHALENE SKELETON. SYNTHESIS OF (±)-ISOCARIDIENE

ABSTRACT

Synthesis of isocaridiene, an isomeric compound of natural sesquiterpene caridiene, is described starting from myrcene. Dehydration of tertiary alcohol leading exclusively to isocaridiene was in agreement with the semiempirical and ab initio quantum mechanical calculations.     

REACTION OF ORGAINIC-TELLURONIUM YLIDE XI.A FACILE SYNTHESIS OF DERIVATIVES OF BISCYCLOPROPANE

Some telluronium salts react easily with 1,4-bis(3-substitutedphenyl-3-oxo-1-propenyl)benzene and 1,5-disubstituted phenyl-1,4-pentadien-3-one to afford derivatives of biscyclopropanes in 61.8-88.8% yield.     

STUDIES ON THE SYNTHESIS OF(±)-CEMBRENE-A

A precursor 2 of cembrene-A(a termite trail pheromone)was prepared fromgeraniol through 7 steps.     

SYNTHESIS OF (±)-FARNESYL FLAVANONE AND FARNESYL ACETOPHENONE

ＳＹＮＴＨＥＳＩＳ　ＯＦ　（±）－ＦＡＲＮＥＳＹＬ　ＦＬＡＶＡＮＯＮＥ　ＡＮＤ　ＦＡＲＮＥＳＹＬ　ＡＣＥＴＯＰＨＥＮＯＮＥ￥ＳＹＮＴＨＥＳＩＳＯＦ（±）－ＦＡＲＮＥＳＹＬＦＬＡＶＡＮＯＮＥＡＮＤＦＡＲＮＥＳＹＬＡＣＥＴＯＰＨＥＮＯＮＥ￥ＣｈｕＳｈｅｎ...     

A FACILE,HIGH YIELD SYNTHESIS OF γ- AND δ-HYDROXYAMIDES

γ- and δ-Hydroxyamides can be prepared in high yields by heating a lactone with ammonia in a pressure tube. The ammonia can be removed by controlled evaporation with ice/acetone cooling.     

A FACILE SYNTHESIS OF HETEROCYCLE SUBSTITUTED CHALCONE AND 5-NITROFURANYL OLEFIN DERIVATIVES

Reaction of heterocycle substituted telluronium salts with aroma-tic aldehydes under mild conditions gave corresponding chalcones.In thepresence of dibutyl telluride,2-bromomethyl-5-nitrofuran condensed easilywith aromatic aldehydes in THF to afford corresponding olefin derivativesas one-pot reaction.     

FACILE SYNTHESIS OF 4-AMINO-4-DEOXY-4''''-DEMETHYLEPIPODOPHYLLOTOXIN

4-Amino-4-deoxy-4′-demethylepipodophyllotoxin has beendirectly synthesized from 4′-demethylepipodophyllotoxin and HN_3in the presence of BF3·Et_2O,followed by hydrogenation withpalladium on charcoal as catalyst.     

A NEW FACILE METHOD FOR THE SYNTHESIS OF AZACROWN ETHERS BY USING BENZYLSULFONAMIDE AS A SOURCE OF NITROGEN

Benzylsulfonamide was used as a source of nitrogen in the syn-thesis of azacrown ethers,and the cyclic intermediates were easily deben-zylsulfonylated by treating with CaF_2/H_2SO_4 to afford the azacrown ethers.     

STEREOSELECTIVE TOTAL SYNTHESIS OF(±)-4α(H)-EUDESMANE

The first stereoselective total synthesis of the biomarker(±)-4α(H)-eudesmane 1,starting from(-)-carvone in five steps,has been described.     

STUDIES ON THE PRENYLELAVONOIDS PART Ⅵ SYNTHESIS OF (±)-AMORITIN

ＳＴＵＤＩＥＳＯＮＴＨＥＰＲＥＮＹＬＥＬＡＶＯＮＯＩＤＳＰＡＲＴⅥＳＹＮＴＨＥＳＩＳＯＦ（±）－ＡＭＯＲＩＴＩＮＬｉａｎＹｕｎＺＨＡＯ；ＦａｎｇＪｉｅＺＨＡＮＧ；ＹｕＬｉｎＬＩ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＡｐｐｌｉｅｄＯｒｇａｎｉｃＣｈ...     

C-4 EPIMERIZATION OF α-D-GLUCOPYRANOSIDE: A FACILE SYNTHESIS OF 4-O-ACETYL-α-D-GALACTOPYRANOSYL DERIVATIVES

An unexpected epimerization resulting from the reaction of α-D-glucopyranosyl derivatives with DAST is described. The reaction of 3,4-di-O-acetyl-1,6-di-O-trityl-β-D-fructofuranosyl 2,3,6-tri-O-acetyl-α-D-glucopyranoside (1), methyl 2,3-di-O-acetyl-6-O-trityl-α-D-glucopyranoside (6), 2,3-di-O-acetyl-6-O-trityl-α-D-glucopyranosyl 2,3-di-O-acetyl-6-O-trityl-α-D-glucopyranoside (13), and 2,3-di-O-acetyl-6-O-tert-butyldiphenylsilyl-α-D-glucopyranosyl 2,3,4,6-tetra-O-acetyl-α-D-glucopyranoside (14) with DAST at 0°C did not give the expected C-4 fluorodeoxy galacto derivatives, but instead, the corresponding 4-O-acetyl-3-hydroxy-α-D-galactopyranosides in yields of 52–78%. When the treatment of 6 was carried out at ?25°C for ～5 min the corresponding diastereomeric 4-O-diethylaminosulfinates (9a,b) were isolated as the major products (40%). Evidence suggests that the epimerization reaction most probably resulted from an intramolecular displacement of the intermediate diethylaminosulfur difluoride ester or diethylaminosulfinyl ester by the neighbouring acetoxy groups.     

A FACILE SYNTHESIS OF AZACROWN ETHERS WITH INTRAANNULAR PHENOLIC GROUPS IN A TWO－PHASE SYSTEM

ＡＦＡＣＩＬＥＳＹＮＴＨＥＳＩＳＯＦＡＺＡＣＲＯＷＮＥＴＨＥＲＳＷＩＴＨＩＮＴＲＡＡＮＮＵＬＡＲＰＨＥＮＯＬＩＣＧＲＯＵＰＳＩＮＡＴＷＯ－ＰＨＡＳＥＳＹＳＴＥＭ￥ＧｕｏＰｉｎｇＸＵＥ；ＣｈｅｎｇＴａｉＷＵ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，...     

FACILE SYNTHESIS OF POLYSUBSTITUTED CYCLOPENTENYLAMINES OR γ-HYDROXYAMIDES BY SAMARIUM DIIODIDE

ABSTRACT

Promoted by SmI₂, γ-Hydroxyamides or polysubstituted cyclopentenylamines were synthesized from 1,1-diaryl-2,2-dicyanoethylenes or diaryl ketones and cinnamoyl amides under mild conditions in good yields.     

SYNTHESIS OF ANALOGUES OF HUPERZINE A

A new Lycopodium alkaloid huperzine A (1) possesses a potent inhibitory activity ofacetylcholinesterase. Six structurally simplified analogues of huperzine A, compound 6, 7, 8, 12,13 and 15, were prepared and the inhibitory activities were evaluated.     

INSERTION OF PTC-GENERATED DICHLOROCARBENE INTO C-B BO ND.A FACILE SYNTHESIS OF KETONES FROM ALKENES VIA ORGANOBORATES

The insertion of dichlorocarbene generated from chloroform byPhase Transfer Catalysis(PTC)into carbon-boron bond of dialkylborateanions 3,obtained by method A and B,resulted in the formation of the inter-mediates 5,which were oxidized with alkaline hydrogen peroxide to give thecorresponding dialkylketones in 36-77.9% yields.